Woah, I've never encountered someone with a story so similar to my own ...my sex drive isn't/wasn't as high but I definitely was more sexual as a child than I should have been. But from what you're saying, those experiences with your cousin definitely could have affected you. Mine were the same, just faint memories with my cousin but since I've been in therapy it's helped clarify and sort of put together the pieces. Have you been talking to anyone? It certainly helps, even if it does feel embarrassing. Making sense out of your past helps so much with the present. And a T will definitely have some really good insight, especially if you tell them everything you wrote here.