Three years ago, you survived having sulphuric acid flung at you by the accomplice of a violent ex-boyfriend, destroying all the skin on your face, neck and hands and leaving you blind in one eye. What was it like the first time you looked in the mirror?

I don't think it was really one defining moment because my face was changing all the time and I didn't risk it for a while. I'd catch my reflection by mistake and that's strange, not to see something that's always been there and instead there's something alien in its place. You'd wake up in the morning and be cleaning your teeth and you'd expect to see your face, but it wasn't there any more.

The acid also burned your throat.

Yes, it damaged my oesophagus. Three strictures formed out of scar tissue, which makes it hard to swallow. I used to have operations to dilate my oesophagus every two weeks, now it's every three months. I can't eat meat. At the beginning, I had milkshakes and I was on a drip for a year. Now I can eat softer foods and go out to restaurants with my friends. I just have to chew quite slowly!

Is there any food you really miss?

I quite like a bacon sandwich with ketchup.

You have just finished filming a series for Channel 4 that sees you encountering others with facial disfigurements. Did you find you had many experiences in common with the people you met?

We had all faced discrimination and that causes similar emotions. We all knew what it felt like to feel different.

What kind of discrimination?

People might treat you differently or avoid talking to you, or stare at you on the street. But there are good and bad reactions. Anywhere, you're going to get people who are ignorant or rude but it's not the whole of society. I don't think my life is doomed because I look like this.

Are we too concerned with appearance?

Not everybody. Obviously, there is a pressure to look a certain way. But for me this experience has been positive. I've realised that not everybody discriminates.

How do you cope with people looking at you in the street?

I like to tell myself people look at me for all sorts of reasons. Maybe they're staring because they're shocked or maybe they recognise me from TV, or maybe they just like my shoes – especially women, because we all look at each other's clothes and hair.

Do children ever ask you directly what happened?

Yes, I was on holiday with my sister recently and we were on a trampoline with some children and one asked me: "What happened to your mouth?" I didn't mind because it was curious, innocent. I just said: "I had an accident, I'm taking medicine and I'm getting better." In Britain, we think it's best to say, "Look away, don't stare," but it's better to be open about it.

The third anniversary of your attack is coming up on 31 March. Does the date still haunt you?

The way I feel about it now, I've been very lucky to recover. Not a day goes past when I don't think how grateful I am I survived, that I recovered and that I feel like a young woman again.

Have you forgiven your ex-boyfriend, Daniel Lynch, or the man who threw the acid, Stefan Sylvestre?

Not really. I've had a lot of therapy about moving on and not looking back, so I try not to think about it. They've never shown any remorse for what they did, they've never apologised and they've never asked me for forgiveness. So there hasn't been an opportunity for me to give it.

Your 2009 Channel 4 documentary Katie: My Beautiful Face attracted 3.3 million viewers. Were you surprised?

Yes, pleasantly surprised. To get a response like that was like the missing piece in the jigsaw to say it was OK to be me, and I never underestimate what that gave me. It's one thing for your mum to tell you that you look OK, but she's your mum and she has to tell you you're beautiful. It's not the same as a stranger telling you.

Didn't Simon Cowell get in touch afterwards to congratulate you?

Yes, it was brilliant. He contacted me to say well done. Then I got the opportunity to meet him in person and he was very supportive when I launched my charity [the Katie Piper Foundation, which helps burns survivors], he became one of its patrons. He's just so lovely: kind, caring, funny and down-to-earth.

You've published a memoir, Beautiful. How did you go about writing it?

Part of my psychological therapy was to write a diary every day. I wrote it for two years and I had a lot of time to reflect so when I started working with the publishing house, I used my journal for the bare bones and an editor worked with me. It took me two to three years to write the book.

How did your parents react to the book?

My dad said he'd only ever read Moby Dick at school and he read the book in one day, which is quite good for him. My mum wrote me a lovely letter and said: "I wish these horrible things had never happened to you but I'm so proud of the person you've become."

Do you wish the attack had never happened, or do you value the person you've become too much to erase it?

I wish I'd never experienced such violence and evil because that's quite frightening. I wish I didn't have my medical problems in terms of a shortened life expectancy. But I don't think: this has ruined my life. Actually, living with burns and being different is a very fulfilling life. I'm at peace with who I am. I don't wish for any woman to have gone through that and, obviously, I'm glad my attackers have been brought to justice so they can't hurt anyone else.

Do you remember the pain?

I try not to think about it any more. I'll never forget it, but a lot of my therapy has been about moving on. It was the worst pain I've ever experienced.

You've undergone more than 40 operations. Do you get used to surgery?

I've got a really good professional relationship with my surgeon, Dr Mohammad Ali Jawad. I trust him so I'm not frightened. Surgery helps me get better and I've accepted it as part of my life. I know I'll always be disfigured but the scars are fading and my skin is becoming more supple.

Have you found it difficult to form relationships since the attack?

The support of my doctor and my parents means I have two good male role models who have stopped me labelling all men as horrible. I'm not frightened of men but I'm probably more sensible and cautious. I am ready to have a boyfriend, someone who loves and accepts me as I am.

Well, you never know, someone might get in touch after reading this...

Yes – you could come to the wedding!

Katie: My Beautiful Friends starts on Channel 4 on 22 March at 9pm