I'm on day 6 now with no weed and no booze after 6 years of daily use. However, I had quit before that for 2 years after 4 years of use. I remember having suicidal thoughts the first time I quit but, it was strange. I didn't want to die, but when I shaved, I'd get mental images of slitting my wrists. When I was at the train station, I'd imagine jumping in front of the train...things like that. Eventually it passed and, in retrospect, I think it was a result of all my self loathing and shame coming to the forefront of my mind after 4 years of keeping it all repressed with drugs.
Try to analyze your thinking and the images that your mind presents you and decide whether you really are suicidal, or whether these feelings are a result of repressed emotions coming to the surface. I definitely agree with Need to Quit that being stoned is better than being dead.
Moreover, I was seeing a psychologist at the time I had those thoughts, so I imagine that any thoughts of this nature should be shared with someone, and preferrably a professional if you can, as they can give you the most objective feedback on your situation.
Good luck, and hang in there everyone. It's kinda funny. I've often wondered about how many people are having sex right now in the world but, it never occured to me to imagine how many people in thw world are struggling to end their addicitons at the same time. It's like sharing a birthday, or something like that