It's worth posting as background information about myself and a far-from-complete retrospect of my adolescence.
Bearing scars from my own attempt, I can only offer the phrasing which caused me to rethink things.
Suicide is using one's free will to destroy one's free will. It's the ultimate useless act. In a society where our lives are as much defined by our deaths, is it really sensible to define yourself that way?
Ultimately, none of us are Herakles, Orpheus, or any other famous hero who had their reasons. We're small, tired, and broken people who should be ashamed to die until they've won some victory for mankind. More pointedly, until they've made life easier for some other person in their very situation.
After all, who could explain it better than one at the end of their rope?