Overcoming Trust Issues

:tough:So Ive been with my girlfriend for about 6 months now. We met over her summer break.She goes to school a few hours away. We've met quite a few times before we got together (mutual friends) and shes really nice but shes been hurt before in past relationships and ive been hurt before but my view of trust has been distorted from since i was about 7 (Parent drama. Dont feel like going into it). She was here for about 2 months before she went back and there were absolutely no issues at all. When she went back to school it was a matter of me getting over the fact that she has more guy friends than girlfriends. I met most of them when i went to visit her and that solved that problem. Every now and then, due to stress, she seems un interested in talking to me. Even though Im 100% sure its due to stress, i still have the voice in the back of my head thinking something more may be going on. Basically what Im trying to say is that she hasent given me any reason to not trust her or to think that she has cheated on me, but there is still the anxiety there. i just read into things more than I should and I cant help it but here I am admitting that Im looking to fix this problem before it really starts to show itself. It hurts me mentally and physically and the only time everything is fine is when we are together. Im guessing the distance is throwing me off. But even right now, we got into a little argument about a month ago and there was about 3 days where we didnt talk and the other day out of absolutely nowhere, my mind started telling me hey what if she did something with someone else during those few days? which I know is absolutely not the case because of how she fixed the issue and if she did, she would have told me or she would be with that person right now. So Hi. Im a crazy person.