I had my first kiss aged 15 on board a ship steaming through the Solent. I think that's rather romantic. It was a decent-sized boat - it had to be, I suppose, because it was full of wheelchair users like me. The two of us sneaked off down to a lower deck where we could be on our own. My stomach was tingling and twisting. Admittedly, that might have been sea-sickness. But it was still a dreamy moment.

At the time I was at Treloar's, a specialist boarding school in Hampshire for pupils with physical disabilities. I went there from the age of 12 to 19 because I had brittle bones, a genetic disability that results in extremely low bone density. (I have broken my bones about 100 times over the years, and had more than 50 operations - I have lost count of the exact number.)

This particular year, my house had hired a boat to go out with our housemaster, staff and parents. They invited along a group of our friends from nearby Frogmore youth club, and it happened that I was dating a guy from Frogmore called Paul. And that's how we ended up snogging on the Solent.

I had met Paul about six months earlier. One of my close friends at school was Nicky Bradley, who had epilepsy. We started going to Frogmore together and met up with Paul and his best friend, Porky. We all got on and Nicky ended up dating Porky, and I started going out with Paul - it was great for a while. Paul was able-bodied and handsome, or at least that's what I thought then. But we were worlds apart. He was a nice enough chap, but not someone I would ever have considered marrying.

That's an awful thing to say. We were a bit like that at Treloar's, though. It was a very highly thought-of school, and you ended up being a little snobby. Nicky and I tended to see the Frogmore boys as slightly beneath us. And I was always one of those kids who would say, "I'm not going to lose my virginity until I get married," so nothing was going to happen as far as I was concerned. Well, not too much anyway.

In those days I was very ambivalent about sex; I still am in some ways. But even as a child I would be daydreaming about husbands, sex and boyfriends, and I used to fantasise a lot. I have always wondered if my disability played a part in this. Even if only subconsciously, you do realise it is not going to be as easy for you as it is for able-bodied girls. So you wonder if your fantasies may be all you will have. I was always terrified about breaking something - what if my leg got caught and snapped? What if my hip broke in the heat of the moment? Also, I was always very particular about who I would want to have sex with.

In the run up to my 16th birthday, all this began to be an issue between me and Paul. He had never had a problem with the fact that I was in a wheelchair, and pretty soon he wanted to take everything a step further sexually. I remember thinking, "I want to be married first - and preferably not in a hip spica." (This is a plaster cast that runs from your toes up to your waist, with a hole cut out so that you can go to the toilet. It requires you to lie completely flat for six to eight weeks.)

Then, a few weeks before my birthday, we had a school exchange with a French college for young people with disabilities. One of the guys who came over was gorgeous. He was called Romuald, and all the girls fell in love with him. He was a leg amputee from a bike accident. He was kind and sweet and devastatingly charming, and the two of us had a wonderful teenage romance. It was such a great ego boost that it gave me the confidence to end the relationship with Paul, even though Romuald and I were only together a week before he went back to France.

By now, my life was beginning to broaden out. I had started doing my A-levels, which meant I had to go out to Alton sixth-form college for lessons. That was where I met a young able-bodied guy from Farnham called Barney James. He was fun and kind. We ended up dating for two years, and he was the person I lost my virginity to at 17.

Barney was a couple of years older than me and could drive. Although I fancied him, the first weekend we ended up back at his house we didn't have sex. We'd gone to the pub for the evening, and Barney was so drunk he just collapsed on the floor and snored all night. (It wasn't long afterwards that I discovered he was an alcoholic.)

We made up for that first night, though. The first time was painful but I needn't have worried about breaking anything. From that moment on we were always bunking off for nookie. We used to sneak back to his house and be at it like rabbits. For me it was a whole new adventure.

At Treloar's, you would spend weeks at a time in what were called "independence training" flats. The staff would make a point of popping in every five minutes to double-check that you were doing the right thing, especially if someone of the opposite sex was in there with you. One afternoon Barney and I were in the throes of sex in the living room, when there was a knock on the front door. We went into panic overdrive. I dressed at double speed while Barney managed to crawl into the wheelchair-access space under the basin. Then I slung all his clothes and his boots under the bed.

When I opened the front door it was the housemaster, with two guests he was showing around the boarding houses. People know me today for my roles in The Office and Eldorado, but I was an actor even then. I showed them round and they left. And all that time there was this 6ft 2in beanpole of a boy curled up stark naked under the sink.

With the kind of sex we were having I will never know how I did not break every bone in my body. Given half the chance I would swing from the chandelier. But somehow I got away with it. I think it is to do with the fact that I was relaxed. Plus my hormones were kicking around, which I feel must have had a very positive impact on my body. My experience with my brittle bones has always been that if I tense up, it makes me much more likely to break something. The times I have fallen and got injured are inevitably the ones when I have gone through that process of watching myself hitting the floor. During sex, of course, I'm not thinking like that, so in many ways it liberates me from the disability for a while. But I also think that as you get to know a partner, they realise what you feel comfortable with and what your limits are.

So the sex was great, but it was always a hectic, intense relationship. Barney's alcoholism played a major part in that, but it never occurred to me that my disability did as well. After being together for a good two years, and having such an active sex life, I assumed he was OK about my being in a wheelchair. It wasn't until we split up that I found out that he did have an issue with it. That was when he admitted that for the first few months, at least, he was embarrassed about being seen with me, and about having a girlfriend who was a wheelchair user. That rather stunned me. All the time we were together, we never really discussed the disability issue in depth. It may sound odd, but we just rarely went there. I think that's partly because I was a very confident, bolshy 17-year-old who had been rock climbing and abseiling. Perhaps I was just very persuasive in helping him not to worry about it. But it still tore into me to hear my first real boyfriend and my first real love admit these thoughts.

In the end it was getting cast in the BBC drama Eldorado that put a finish to our relationship. I had been at boarding school full-time, so when I went off to live in Spain - and suddenly there were no rules except for turning up to work on time and learning your lines - I went mad for a year. I discovered nightclubs and that was it. I would go out at midnight and crawl in at 7am three nights on the trot, week in, week out. Don't ask me how, but I didn't injure myself.

Out clubbing, I would flirt with guys and kiss and mess around, like any young woman, but that was when the wheelchair started to play a negative role. I have lost count of the amount of times that men have come up to me in pubs and clubs and within five minutes come straight out and asked: "Are you capable of having sex?" It used to make me so angry. Why would anyone think that that's an acceptable question? Did they possibly think they were being "kind" to me in some way? I used to temper my response depending on whether I knew the person but generally I was thinking, you wouldn't ask anyone else that, certainly not without expecting to be slapped.

I have found that there is a kind of morbid attitude towards disability and sex. People think that because you are in a wheelchair you are not capable - that you can't physically do things, or feel emotion, or express that feeling physically, or shouldn't be allowed. Did these guys fancy me though? I don't know. I suppose they saw a pretty young woman, a petite blonde, in a wheelchair and they would come over to say hello. But I don't kid myself. I was always with a bunch of attractive women - friends, actors on Eldorado - so they probably came over because of them in the first place, and then got chatting with me.

It's a situation most adolescent girls fret over. You don't feel as attractive as your friends and you worry you will never get a boyfriend. Able-bodied women are always saying to me, "Oh, we know just how you felt, Julie, we were just the same in our teens." I have to say I don't think it is the same at all. Although I understand my able-bodied friends are trying to empathise with me, it doesn't actually make me feel any better. The truth is that all the typical teenage angst about relationships is a hundred times worse if you are in a wheelchair. I couldn't even open the door to get into the club myself - let alone leave with a bloke on my arm. Almost all the boys were just too frightened to come near me.

One thing I have rarely experienced is one-night stands: they aren't much of an option for wheelchair users. It's always been relationship first, then sex. Over the period of getting to know someone, they would get to know what I was capable of. Then the barriers would break down and they would realise that sex with a wheelchair user is not so much of an issue. It has always had to be that way round, and I don't think I lost out by it. It's not something I think about on a daily basis - unlike the idea of being able to walk down the street arm-in-arm with my lover holding hands, or having him squeeze my bum unexpectedly as I'm doing the washing-up, or looking him in the eye as we stand and kiss. I think about those things all the time.

There was also the problem that a lot of actors and celebrities get, of attracting unwanted attention, and my disability didn't make me immune from that. One guy started a correspondence. He would write, "I am going to come and find you and get you and take you away from all this ... You will never have a problem again ... I want to make love to you ..." Eventually it came to a head when he sent me a drawing that he had made of a church and a graveyard. The graveyard contained a tombstone with my name on it. I freaked out and took the letters to one of the Eldorado producers. By coincidence, he had received a phone call from this man a couple of days earlier. Apparently he was very convincing, saying, "I'm a mate of Julie's and I can't get hold of her. I'm in Spain on business and it's a chance to catch up." I had to go into hiding for three days.

By now, the guy who played my boyfriend in Eldorado, Kevin Hay, was my boyfriend in real life. Kevin played the character Razor, and was written in after we had been running about four months. Kevin is able-bodied, and it was brilliant of the Eldorado production team to write that storyline, because it raised a lot of issues.

Kevin and I got on really well. There wasn't any one particular signal that made it clear he fancied me - I can't even remember the first time we had sex. He was just so laidback. He had lots of gay and straight friends and never saw the world in a negative way. He was so different from what I was used to. He was English but he had been living on the Costa del Sol because his parents had moved out there years earlier. When Eldorado eventually finished, Kevin stayed in Spain. Inevitably, our relationship petered out.

After that I spent years single. I used to get very sexually frustrated, as well as feeling very alone. On the plus side, when I came back from Spain I began to get on really well with my brother. Rab has a large group of loyal friends and they all treated me wonderfully. They were so protective. That in itself was incredibly frustrating, though, because there were a couple of guys in the group that I found attractive and would have liked to date, but since I was their mate's sister, there was no way they would come anywhere near me.

The person who really opened my eyes to what people with disabilities are capable of sexually is an old friend, Mik Scarlet. Mik is a wheelchair user and an actor/presenter as well as being an extremely talented musician. When he was about seven years old his spine collapsed and he became paralysed from the waist down. He's gorgeous, with white-blond hair - like Billy Idol on wheels. And very sexually confident. Once Mik and I were asked to do a porno movie together. (There is quite an industry for disabled porno stars, because there is a group of men and women who are aroused by watching people with disabilities having sex.) We said no to that, but Mik taught me a lot about sex.

He would tell me how you can give yourself an orgasm by touching areas that aren't associated with the usual erogenous zones. He explained about how to turn people on who might be paralysed from the waist down. His point was that there are lots of ways that people with disabilities can have sex that may not be the conventional way. It was a major eye-opener.

Once, we were in Ian Beale's chip shop on the EastEnders set, being filmed for a documentary, and we were talking about sex, as we usually did. Mik was telling me about ways of turning yourself on, as well as your partner. I suppose I was sceptical and being a bit of a killjoy, so he said, "Right, get ready." Then he made me open my mouth as if I was yawning and he very gently stroked the roof of my mouth with his finger and it was amazing. What a turn-on - right there in the middle of Ian Beale's chip shop. I bet they'd never dare script that into EastEnders.

Like I said, for a long time after my relationship with Kevin Hay finished, nothing much happened. Then I went to a conference on brittle bone disease in America, and there I met one of the expert researchers on the subject. He was part of the team that invented a medication that helps increase bone density. We got chatting and hit it off. I really liked him. It was the first time in years that that had happened and we ended up having a fling - and it was the best sex I have ever had. One of the things that made it such fun, and why it felt so naughty, was that he was highly respected by all the people at the conference, and yet there we were sneaking into the hall after we had been up to it. I think one of the reasons the sex was so amazing was because he knew everything about my disability. I was able to relax with him completely.

When I got back to England after the conference I wrote to him and expressed how I felt, without being too dramatic and putting him off. I said I wondered if he wanted to take it a step further. If he had said "come to America", I would have dropped everything, including the acting, and gone. But he never replied to the letter. It was really hurtful and it took me a while to get over it. I had never met a man like that before, one that I could have married tomorrow. I thought I'd never find a man like that again.

Then my lovely Andrew came along. That changed my world. About five years ago, when Andrew took voluntary redundancy from the company he was working for, he decided to give some of his redundancy money to a charity, and he happened to read an article about me and the charity I had set up, The Disability Foundation. He'd never watched The Office so didn't know who I was, but he managed to get hold of my email address. He explained that his father was disabled and he had grown up around disability. He added that he would like to donate to my charity. I sent him the contact details and thought nothing more about it. It had completely gone out of my head when, about a month later, he wrote back and asked if there was anything else he could do volunteer-wise. He'd mentioned that he was in IT, and at the time I needed a website designed.

We arranged to meet in London for dinner on a Friday night, and we were attracted to each other pretty instantly. We talked about business, but I think we knew we liked each other. Andrew is the nicest person I have ever met. He's 6ft 2in, but the most gentle man. He's a couple of years younger than me and comes from a very calm household. (Mine was filled with rows and arguments and plate-smashing.) Eventually we started dating, and he is totally accepting of me and my disability, which is wonderful.

More than four years in, we are living together, and it is fantastic. There is a lot I can and want to do around the house - I can do the washing, the cooking, the ironing, that sort of thing. But there are a lot of things that I can't do, and some of them are just simple things. I can't empty the bin in the kitchen because it is too heavy. I can't reach certain items. I can't easily go out into the garden to water the plants. I can't change the bed sheets. And you get sick of it, because you are always having to say, "Would you mind .. ? Please could you .. ?" Thankfully, Andrew understands the issues and we have a cleaner to help me out. He works long, hard hours and I don't want to spend the whole evening asking him to do too much, although he does have to help me a little. One thing I regret is that now I am into my 30s, my body can't cope with sex so much. It has been so battered by brittle bone disease ...

It is an emotional battle, because you want to make love with your partner, but your body is just not capable. By the end of each day I feel shattered, and when I finally get into bed it takes the first half hour just for my muscles to start relaxing; the last thing I am thinking about is sex. I feel gutted that I'm not able to have it as much as I want, and I also feel so guilty because I am not offering it to Andrew as much as I know he would like.

The truth is, my relationships have always been affected by the fact that I am a wheelchair user, and they always will be. I am not a romantic. I don't kid myself on that subject. And I know it is harder for disabled women to be in relationships than it is for disabled men. You see a lot of disabled men going out with able-bodied women, while the reverse is much less common. I feel it is because women look at life differently. We tend to have an attitude of acceptance, even of mothering. And image is less of an issue for us than it is with men.

There have been times when I thought I was going to be single for the rest of my life. I thought, no one is going to love me. But the spiritual side of me told me that wasn't going to be the case; that it was all waiting for me, waiting for the right moment and the right person. You can't get away from the fact that being disabled does make finding and keeping a relationship much harder. But who said sex, on wheels or otherwise, isn't complicated anyway?

· Some names have been changed.
the-disability-foundation.org.uk