It only has to be bad enough to make you want to quit.
Addiction is one of those things that thrives on isolation. So "getting help" of some sort--some kind of power other than your own--greatly increases your chances of success. It's part of the treatment, so to speak.
You don't have to ride the elevator all the way to the bottom. The bottom--the REAL bottom--is death. Anything short of that, well, you can always fall further. Personally, I think it makes little sense to prolong the suffering any longer than necessary.