It's ok, don't worry. I had the same ''problem'' 2 years ago. It's had to forget her and take her out of your mind, but you have to thing, what if someone has a crush with your gf? You have to go out meet new people, new girls, do things that you like. I did the same, sometimes I thing about her, but I know that she is with someone she wants, and that's enough for me.