I am so sorry you are suffering so much. I know when people have these thoughts and compulsions it's agonizing, especially because it is so difficult to share them with others for the fear of being harshly judged.

One thing that, I think, is important for you to do is to acknowledge your strengths in the fact that you have never acted on those thoughts. When the thoughts are compulsive, it's very difficult not to act on them, so you have a good reason to feel good about yourself in that regard.

If I were your therapist, I'd work with you on trying to understand the desire to do things to children. Not the origin of it but in terms of what kind of emotional reward this desire is trying to get. Because every behavior has a purpose. You don't need to know the cause of it to understand the purpose of it.

And, by the way, many people who were abused DO become abusers. The majority of them, in fact And vice verse most abusers (if not all) were victims of abuse at some point. It's a very inconvenient fact for people to digest but it's a fact. We, as a society, love to divide the world into "good" and "bad" people. We believe that the person is either a victim or a perpetrator and that they can never be both when, in most cases, they are both, but this is too complex for our simplistic brains to digest.

That said, I can only repeat that you may not be able to ever uncover any memories of violations done to you, which does NOT mean you can't work on your compulsion in the here and now. The way to go with this IMO is to try to understand the desire itself and what it is about doing those things that would make you feel better. That alone could give a wealth of information about how to proceed.

I do not, however, think that it'd be appropriate for you to analyze this on any public forum. You need to go on some serious search for a therapist who can do this work with you and do it that way. That's the only way for you to address this problem at this moment IMO.