Good stuff in this thread.
Tom, the main thing is to realize that happiness is something that ultimately has to come from inside of you. You can't rely on other people for it, because other people can be unreliable. You've found that out. That doesn't mean you can't trust and love and let them into your life, but you can't turn over your self-worth.
Graduation and geography have given you the opportunity for a clean break. Take advantage of it. Sometimes high school is something you just survive to get to the good part.
College is fun, and it's an opportunity to reinvent yourself. Of course, if you're like me, you'll eventually get tired of trying on new hats and you'll just start being who you really are, and that'll work out okay. You might be amazed at how easily the people closest to you saw right through it all, and liked and loved you for who you were, not who you were trying to be.