First of all I'm so sorry, I didn't see this thread earlier, just saw it.
While reading your post I felt that you are already doing the best that you could have done in this situation, You are going to college, you've started a band, are meeting new people and most importantly are dating someone. I'm not suggesting that dating again after a breakup is the most important thing to do but it is defiantly important to go out with someone new after a period of time, and most importantly going out with the right person. And here also you seem to have done what's best, You are dating a person who loves you even though you have clearly told her how you feel and what your situation is, She knows exactly what you have gone through and still she wants to be with you, that's good for you. It's better to be with a person who loves you then to be with someone whom you love. Luckily you like her a lot too (you should have felt guilty if you were being with her just for the sake of being with someone, but as you said you like her a lot too so there's absolutely no need to feel guilty).
And please never think that you're being selfish for being with someone who makes you feel good about yourself. Roy Croft once said “I love you, not only for what you are, but for what I am when I am with you.” We all love to be loved.
For now take your time, I'd say be with her, and as time passes things will become clearer.
And Patio, just because you don't have a girlfriend doesn't mean that you are allowed to give bad advice