Can I get some relationship advice? I am treading water!

Ok, I have been dating girl #1 since December. I just graduated school, and she is a freshman. Things are great: I trust her more than anyone else I have ever dated, I LOVE her family, and we are great with one another. Although I know that I could marry girl #1 and have a great and happy life with her, I still have some occasional feelings of being locked in (issues from a previous two year relationship when I was cheated on). I am happy when I am with her, but I must admit that I sometimes wish I still had the ability to go out, flirt, and meet girls. I would NEVER cheat; that is not an option. But I am being honest here.
Also, we both recently met through a mutual friend girl #2. She is beautiful, a great person, and we share many mutual interests. I can also see myself with this girl in the long run. A definite minus is that she lives 3 hours away (although I might be moving close to her and far from girl #1 soon for a job). To be honest, I sometimes think that I am only thinking and stressing over what I can’t have.
Can I get any advice? I am really, really upset over this! I love girl #1 but I can’t think of breaking up with her 99% of the time because I am her first love and she has been perfect and I have no reason to…except that I feel guilty over this crush on girl #2.
HELP!