I think if you are questioning your intake there is a problem for you. It certainly sounds like our stories. At some point - and there's no telling when - you will cross over into addiction/dependence; if you aren't already there.
As far as the GF, you both need to work on yourselves, it sounds like. That's not going to happen while she drinks the way she does and while she has the anger that she has.
I hope you can find some peace in this. I would have left her too. As a matter of fact, my ex husband and I both drank, but his caused him to blackout and buy drugs and stay gone for days at a time. That was a dealbreaker for me. I sobered up once we split.