Really, wouldn't it be far more enjoyable to jump off something high with a trampoline at the bottom? Or perhaps a foam rubber pit.
I've had plenty of times, myself, when I've felt like life wasn't worth living. The thing is, though, things always get better. Perhaps they get better, then worse again, ad nauseum, but it's still worth it. Just try to focus on the good things in your life. A few years ago, while dealing with my bipolar disorder at its worst, I made a few CDs while in a better state of mind with songs I knew would make me happy no matter what. When I'd get into my really dark, depressive states, I'd play the CDs, and while they didn't make everything better, they made me realize that it was just a passing phase.
You'll be okay, man. Life is rough, unfortunately, but it's worth living for the good times, however few they may be. And if you ever want a little perspective (as in, your life is better than you think), IM me sometime and ask about how mine's going, lol.
SD