I know where you're coming from. All I can say is that these things happen to us whether we want them to or not and you just gotta deal. Also, relationships at your age just need to go slower instead of faster. I've talked to people who feel the way you do and I honestly can't really give anything more helpful than "just deal". Life's a major bitch. Nothing more about it.

As for being bi-polar: my friends say I'm bi-polar. Dunno if it's true or not, but all I can say is that maybe you should talk to a counsellor or a therapist (or someone like that) to get some help. You don't have to suffer. Another good thing I've learned: when you feel like you aren't being yourself, write it down. Keep a log and after a certain point, just try to keep a separate log for all the good things to do. Once you've done that, compare them and then destroy the log of negative points and keep only the positive one to give better memories. It helped a friend of mine once.