I read something on a blog recently that was fantastic.
The question is not "is this bad enough for me to quit?"
But rather "is this good enough for me to stay?"
And the real question underneath it all is "am I free?"
The point being, you have one precious life, do you really want to settle for "not that bad" (note--with drinking it gets worse) when you could be great, wonderful, free? You don't have to wait until things are awful to do something about this, you really don't, so don't get stuck on the idea that the only acceptable reason to quit is if something awful happens.
The blogger is Laura McKowen if you are interested, she writes a lot of recovery stuff.