Now, I don't know how old you are, but I'd guess I have more than a few years on you, given I haven't had an infant to raise for, oh..... a couple of decades. And I can say, on behalf of myself and the other parents here, that most of us have, at one point or another, had to make choices we never really wanted to make for the sake of our children. When I got married, and even later when I had my kids, I never imagined I'd be raising them effectively on my own. But, in retrospect, it was the best thing I could ever have done for them. While they didn't have parents living together, they were raised in a home filled with love, joy, and dreams. Sometimes you have to make the hard choices.
Which would you prefer... Raising your daughter on your own, in a happy home? Or with someone who doesn't love either of you enough to quit drinking, in a home where the cops come knocking every few months?
Just really think about it.