is it my fault?

I have been holding onto to this secret for too long and it haunts me sometimes when I wake up. When I was around 10 years old, I began to be sexual ly assualted by my cousin who was 12. I slept over by his house once and then he got on my back and told me to push back. I said no and I told him to stop but he pinned me down and pushed into me, I felt dirty and sinful because I grew up Catholic in which homosexuality is seen as one of the worst sins you can commit.. That was the first occurrence, over 5-6 years when I went to his house to sleep over the same thing happened, except sometimes I was looking forward to it, this was due mostly to the fact that girls never seemed to like me in school and I was being bullied. It stopped when I reached high school but sometimes when im.alone and im.thinking, it pops into my head and I start feeling awful. I can never bring myself to tell anyone because I feel they will be disappointed. I want to stop thinking about it...any advice?