Dwelling on the past

First off this is a first time thing for me so sorry if I don't get this right and if this just sounds like a lengthy dumb rant. Me and my girlfriend have been together for a little over a year now. We are both in our mid 20's (if that matters). Before we were together we were friends for roughly 4 years. We became friends when Her, myself and a friend of ours rented an apartment together. We became best friends fairly fast and started to do just about everything together. Durring this time she had multiple sexual partners and relationships. I became infatuated with her since the moment we met. She had already had a few relationships and partners before we moved in together while I was still sitting at zero. While we lived in the apartment she lived it up, having causual encounters and just being an average young person. Durring this time I started to feel hurt and sour. Now I'm stuck thinking about these times and have been for quite a few months. She is my first sexual partner so obviously this is my first relationship. Having far less sexual experience than her it is hard for me to come to terms with her sexual history. I am in no way blaming or trying or guilt trip her for what she has done. We have talked about how I feel and she says that she isn't proud of what she's done and wishes she had something to tell me to make me feel better. I blame myself for letting her past effect me so deeply because she tells me that she fell in love with me well before we had moved in together. She was just waiting for me to

First off, I'd like to start by saying that these feelings you are having are completely valid. Resentment, even towards someone you love is never easy to get over. The fact that it affects you so deeply is because you care so deeply. The best that you can do right now is to focus on that. Also, she may have had those casual relationships but she is chose you for a serious one. YOU are the one who means something to her, and YOU are the one she is with now. Will you get over these feelings right away? No. But the fact that you are acknowledging these feelings and being honest with her about them is a definite step in the right direction. So continue doing that, and remember to be thankful of what you have now. I wish you two the best of luck.

Thank you!