Except when the suicide attempt in question has nothing to do with school, the "just a few more years" mentality doesn't really apply. I'm almost twenty now, but when I was eighteen, I attempted suicide because I have a terribly dysfunctional family (three sisters who, for five years of my life, pretended I had died and wouldn't associate with me even though we lived under the same roof, a mother who constantly criticized me for not being pretty enough, and a workaholic father who is the best dad I could have ever asked for, but was never home to help me with my other family.) and I'm physically disabled and it's only getting worse, I'm still a virgin, and the weaker my legs get, the less I have a chance at losing that. I've seen teams of surgeons and doctors but they claim they've done all they can.
I'm in university, I have a really amazing, wonderful, circle of friends, I attend therapy and take SSRI's to help with my mood, I can get jobs without a problem, technically I still can do "everything that makes life worth living", but I'd still kill myself in a heart beat if I could. Attempting suicide the first time made me see how dark and stigmatized suicide is in the reactions of my home town. The only reason I'm alive is because, if THAT was how people were going to react to suicide attempt, I didn't want to cause what would most likely be a more intense reaction to a suicide success.
I'm still quite young, still a teenager, and I realize that the loss of a young life is tragic, but I just don't see myself having much else to look forward to. I've never believed in marriage, I don't want kids, I have no real main goals in life. The way I see it, I should have the option to die with dignity while I'm physically strong. My biggest fear is being in more pain than I'm already in. I'm already at my limit when it comes to the muscle aches and spasms I have every morning.
Waiting a few more years is the absolute last thing I want, because I don't see any hope of improval. It sucks, but it's reality.