Comparing girlfriends previous relationships

I'm in a relationship - about to be married, but I cant stop comparing my relationship with my gf, to those she's had previously. Especially when it comes to our sex life. In the past she had a lot of partners and I found out about some things she did whilt on holidays etc with a previous boyfriend. Now I can't seem to stop comparing that with our relationship. Its killing me. I keep wondering why she isn't as open about sex with me as she was with her ex. Comparing the number of times they had sex on a particular day or where/what they did... wondering if she'll ever be like that with me. I hate it, but I just can't seem to stop myself thinking about it. I told her how I was feeling and she got angry with me saying that I make her feel bad about her past - which is something I never intended. I dont want to keep comparing, but every now and then something pops into my head to make me think about it all over again. I need to stop it before it destroys our relationship, but I dont know where to start.

"Paranoid" - you need to think about this sensibly. The situation is clear, and in my opinion, you shouldn't compare your sexual relationship in this way. People's sexual needs can change over time, so perhaps her previous relationships were more about exploration of new things. There is no reason however, for you to think that a change in her requirements is a problem related to you! Maybe her ex was more experienced than her, and took the lead when it came to sex? If this were the case, the things you know about and are comparing with your own relationship seem less important than you may think!