I'm a mid-thirtysomething who hasn't been involved in a relationship for over 10 years and has never been in any kind of sexual relationship. I thought it was because I was just living for my career, but two and a half years after a career change, which I thought would make a difference, there is none. I get involved in long, tortuous relationships with some unattainable woman which fills years of my life, ending with me professing undying love for her and her running a mile. I seem to stick with friendship, letting time slip away before trying to move on to something more.

I need to get to know someone before I can be intimate with them. Why do women always go for the kind of man they profess to despise: sex- or money- or power-obsessed, and arrogant

This must have been making your life hell: what a distressing predicament. Clearly, you have powerful inhibitions when it comes to making a move on a woman, ones so forceful that you will do almost anything to avoid the risk it entails. I recall feeling like that as a teenager, so I can sympathise - that ghastly moment when you've got to do or say something which commits you irrevocably to having indicated a desire for sexual action. It's the hand on the knee, the move for a kiss on the lips, the unmistakable invitation to do more than just have another cup of coffee at the end of the evening.

I can also sympathise with the way you have been avoiding this situation - developing platonic friendships, where really you are after something else. You are scared witless of being rejected, so much so that you dare not make any move that could lead to it. Key fears might include that she will see you as ugly or pathetic.

You feel emotionally fragile and may have been deprived of unconditional love as a baby and toddler. This left you hankering to be understood, to be mothered and told what a lovely, sweet boy (man) you are. That would make you reluctant to do anything which could upset a woman, like trying to put your hand up her skirt, even when she is hoping you will. If you do see women as mother-figures, you would feel very guilty indeed at doing anything sexual.

Sexual thoughts and impulses in the company of women probably make you cringe. But I imagine that, when alone, your masturbatory life has been quite a busy one over the years. This is maybe something that you are ashamed of. I would guess that one or both your parents adopted a severely punitive attitude to sex when you were small, perhaps fuelled by religious beliefs.

All boys engage in willy-waggling and express sexuality in their primitive ways, but parents vary in their reactions to it. The kind of parents that someone with your problem is likely to have had came down like a ton of bricks the first time their son touched his willy in front of them, so much so that he felt it was the most sinful of all things to have a sexuality.

In later life, every time he found himself in with a chance with a girl, a voice would appear in his head telling him how wicked he was.

You need to see a therapist to talk all this over, preferably a man. He will help you to face the horror you feel about sex but, above all, will enable you to identify what happened in your childhood that so put you off. Clearly, there is a big part of you that is looking for a mother rather than a lover. The therapist can take that maternal role, and it's important they do because, as you know, women do not generally find needy men who want to be boys a turn-on. In fact, desire is often provoked in women by the dominant, masterful behaviour and attributes you describe.

I would suggest going to a Cognitive Analytic therapist (call 020 7928 9292, ext 3769, to find one near you, depending where you live, you may have to pay for it).

Part of getting over what must by now be a full-blown phobia might entail visiting a prostitute and simply asking her to masturbate you. This will get you off the mark and could lead on to intercourse on another occasion. You will feel a whole lot better just to actually have had a sexual encounter.

You should also go and see a sex therapist. They can address the many neuroses that will have developed for you about the smell of sex, and the sights and the sounds and the feelings which accompany the build-up. They can also help you to learn to move from masturbation fantasy to sex with a real person. You may be able to find one through the NHS - ask your GP.

What a tortured time you must have had. But, unlike many other kinds of problem, this one does respond to therapy. With a bit of luck, you could conceivably be enjoying sex within a matter of months.

· Oliver James' They F*** You Up - How To Survive Family Life is out in paperback (£7.99).