Girlfriend issues :/?

I have been together with this girl who I love so much, for about 2 months. We will be together for two months on July 12th, 2011. Recently, every other week I have been getting pretty mad / upset / frusterated while talking to her on the phone and/or texting and she is moving July 21st I believe to San Diego for two years and when we fight or when I'm mad I mention breaking up and stuff and I say stuff how I don't think it will work when she moves and things like that. I really don't want to break up with her and I know she really loves me and cares about me. She thinks im the one for her, her soulmate and I also believe she is mine. We have also been talking about having sex and shes a virgin and im not and she has said sometimes that shes ready and then she says she isn't or she is ready but not at the same time, she wants to have sex but she is scared and we talked about this last night, she said she was mostly scared about being pregnant. I really want to have sex with her but it's not the only thing I want from her or all I care about. I haven't had sex in a while and I really love her and want that special feeling by having sex with someone I really care about and we have been having phone sex and we have done some sexual stuff... Any advice on what to do? Also, recently I've been getting this weird feeling in my chest when she / we talk about phone sex and start to do it but then it sort of goes away. Any advice would be appreciated :).