I went through this struggle myself, wondering weather or not getting a composition degree is worth it or not. I ended up deciding that going to college for composition is an invaluable experience weather you make a career of it or not.
Some of the greats never went to a music school, they just had it in them. However, if you really want to go to music school, if that is what you love, the reason you should go is because you love it, not because you want to make a career out of it. Music was never a secure job option, but if the greats wouldn't have taken those risks, where would music be today? If your music doesn't work out as a career, just remember; those who can't do, teach! That's my backup plan anyway, even if it means getting a doctorate.
That's my 32805/32768. (Microtonal music humor)