I didn't see this earlier..
I'm sorry for you, Meryl. It sucks being depressed, I know.
Do you know if it's bipolar or unipolar..?
I was diagnosed with unipolar depression when I was in high school, after being prescribed ritalin (generic: methylphenidate) to alleviate Attention Deficit Disorder (which I have). Unfortunately one side effect they forgot to mention was it messes with your brain chemistry, and sends you into some serious depression.. I got out of it, though (..though I've never really been 'right' since.) with a mix of meds and a steady regimen of friends and video games. Aah, the glory of escapism.
My reccommendation, don't take it too seriously.. stick with your friends, and let the stress out somehow. I know it might not be your style but just some sort of pseudo-violent means of letting it out of your body and head would probably help a LOT. (a punching bag worked for me.. but playing Grand Theft Auto and dragging simulated people outta thier cars might help just as much for you! ^_^) As for the pills... you might want to take them, stuff like prozac isn't really addictive.. And like most things like depression, with time you will 'grow out of it'.
(after actually reading the thread.... one more thing. This is in NO WAY your fault. Your environs have adverse effects on you, and stress builds up inside. Contrary to what SOME people believe, it's not something you can just 'deal with' safely.)