Oh, well, a long time. I have two cats so I guess I can't really let them just like that. I know, just like the thing : if you kill yourself your dog wouldn't understand.
But more seriously, it was never a big pink joyful life, but when I was 13/14 I still had friends, and could still go out. And had glimpses of hope. So about, between 4 and 5 years since I didn't have a reason to live.