I feel your pain; I went through the same exact thing when I was in high school. The truth is, the vast majority of your peers at school that think they know exactly what they want to do, actually have no idea what they want to do. And the ones that do know will change their minds four times by the time they are in their twenties.
It's just human nature; we don't fully develop as individuals until well after high school. I will answer your question based on my experience:
I had a chance to either go to Berklee, Grambling, or keep my grades up and go to UCLA. I didn't know whether to pursue academics locally, go to a southern college, or keep going with my music. I goofed off junior and senior year, and as a result my grades eventually were not good enough for UCLA; that was one less thing to worry about. I got audition tapes, recommendation letters, etc. for Berklee but never sent them in out of indecisiveness. I got accepted to Grambling, but never went; again due to indecisiveness.
I ended up at Cerritos College, thinking that I could figure it all out in the two years there. I changed my majors from Anthropology, to music, teaching, to Psychology, and back to music before getting married and entering the workforce full time. The vast majority of the kids I went to school with that went off to college ended up right back in the neighborhood a year or two later.
Fast forward to 2009, I'm 26, and I know for sure that I should have gone to Berklee.
My advice? Ask yourself what is more important to you: being happy and broke (but still surviving), or being financially OK and pursuing your dreams as a hobby. That's all it boils down to. If you can't figure it out right now, there's no shame in sticking around locally until you do.
EDIT: wow, 6 posts all saying, pretty much, the same thing. Worth a listen.