1) Has he stolen the lyrics and notes from you in actual paper form? If not, keep hold of them. If he has and you didn't copyright them...tough shit. Most you can do is ask him not to use the material.
2) College is probably your best bet for finding band mates. Most colleges have some kind of community notice board or something where people will advertise their talents. Either look there or put up 'Guitarist/Vocalist looking for band, male, 15, GSOH' or something to that effect. Another thing to do is make friends quick at college and drop into conversations that you're a guitarist/vocalist looking for a band and if you're in luck your new friends may point you in the right direction.