About a girl..........................…

I'm a 14-year-old honors student who needs desperate relationship advice. Obviously I won't make any drastic changes based on an internet post, but I do really need help figuring out what's happening. For the sake of anonymity I will refer to this girl as "Betty". So Betty lives up the street from us. She's a freshman, and her younger sister is in my grade--we're friends. I've been kinda friends with Betty for a few years but we rarely saw each other and I never saw her THAT way. One day though she and a few other friends were over watching a movie. I have no idea how the hell it happened, but by the end we were holding hands. This kind of "hanky panky" went on for a few months until we finally kissed and talked about what we had. Even then though it was awkward because she is generally a quiet girl who doesn't talk a lot about her own opinions. Now I feel like our relationship is kinda dying out. When we hang out our conversations are dry. Furthermore I find it more fun being with my friends than with her. What the hell should I do? Recently I've thought about breaking up but still have mixed feelings. Plus, how would I go about doing it?