The best way to get over the feelings is to completely quit thinking about it. That's hard because I've been in the exact spot. My first post on this forum was about my girlfriend's past. Just don't talk about it anymore and get your girl to quit talking about it as well. If she didn't think you were the absolute best, she wouldn't be with you. Sometimes past events lead to the present moment. Had some things not happened, you two may have never met! Think of it with a positive attitude and when you start to get thoughts (mental images of what happened), simply repeat "It doesn't matter." to yourself.