I like the way ShyBear draws a distinction between sexual acts and sexuality. I would put it this way, though it just repeats what SB has said. Imagine sex with someone and thinking "this is great sex", as opposed to doing the same thing with someone else and thinking the whole time, "I love you".
I had an interesting conversation with a gay survivor recently, and he put it really well. I'll just turn what he said into questions. When you think of waking up on a happy morning and looking at the person beside you in bed, do you want to see a man or a woman? When you think of building your life together with someone, is it a man or a woman? When you think of sharing all your joy and tears, man or woman? Things like that.
But yes, how can one even address such questions as a survivor? Certainly abuse wrecks a boy's sense of sexual boundaries and orientation, and that makes it very difficult for him, as an adult, to build on such weak foundations.
In a way it's like trying to build a house with a general plan in mind, but having no expertise or experience and being able to use only what random materials happened to come to hand that day. What would the result be? Imagine your feeling when you realize that the only way forward is to tear down the house and start over? But start with what? How can one "rebuild" such a house?
There are ways out of this mess, but certainly I would urge recourse to a professional therapist if that is at all possible. I don't know what is available in your area, and perhaps therapy would be very expensive. But what you're talking about is sorting out your life - a pretty major priority!
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)