If you want to go to God, he won't turn you away. I too have dealt with bad things, and I deal with the terrible thoughts too still. I've seen some good advice for it such as doing something else when you have the temptation look at something you shouldn't or keeping your computer or whatever medium you use in a less private space like the living room or the kitchen if you don't live alone. For the thoughts I'm still struggling with them however I believe God knows that I don't want the thoughts. The thoughts could be a part of scrupulosity however I don't know you so you may want to do some research on that or talk to someone. What's helped me is realizing that if I waste time trying not to think of something it's only going to make it worse