i need help with my relationship? 10 points?

OCD is obsessive/compulsive disorder. It's very separate from these images you're talking about. Your OCD may be a way to cope with your past- not only is it a nervous habit, which most people develop after a traumatic past, it's also a good way to spend and fill your time to not think about the hurtful memories. Maybe you did it when you still lived with them and found it as a way to soothe yourself there and you simply find that now you have more time to do it. As for your girlfriend's past- remember that her past (for all its "sexual experiences") made her to be the person you love today. It's not for you to forget, it's for you to accept and love, because those experiences are her. Both problems can be helped with a psychologist- see one if you want to recover from both your childhood and your relationship.

Why are you stuck living in her past, and how do YOU know about it, anyway?

Girls shouldn't go around broadcasting their sexual past to boyfriends. It's a stupid thing to do.. but apparently, it's done.

Along with that so is her past -- that's done too.. It's over. That was then, this is NOW. Right NOW she's seeing you.

Stop being a puss.