I don't think you are supposed to 'stop it'. Let your suicide urges motivate you into making original decisions (that aren't suicide). I think back to my days of feeling suicidal and I see quite clearly that my problem was that I was trapped in certain ways of thinking and behaving. Fear was a huge part of what was keeping me from making positive change.
If you feel you're better off dead, then you've nothing to lose, so you might as well try to feel better before you die. Experiment with making changes that you feel could help, or if you feel that nothing would help, try things anyway... eventually you'll probably stumble on something interesting enough to stick around for.
I recommend regular exercise, healthy diet and meditation as general depression beaters.
Reading this might help
http://recollection.posterous.com/i-am-the-dice-man
Yeah I don't exercise, unless walking quite a bit counts.......I'm usually to tired to do much else, I do attempt to eat healthy but lately I have to force myself to eat most of the time because I have pretty much no appetite even when I am hungry.