You have to understand that what you did was not okay, no matter how drunk you were or how your emotions were all over the place. That doesn't make anything okay, no matter how you try and spin it or how crappy you are feeling. You are in complete control of your actions and you were wrong there. Plain and simple.
As for him being a great father for your daughter, is that really true? He gets along with her well but the night before your birthday he goes out and drinks all night, doesn't come home and the next thing you know he's at work again? I don't know if another woman is involved but this kind of behavior is troubling anyway. How often does he do this? While I'd like to believe that important events like this can just change somebody's life around and rearrange their priorities for them, I just can't believe that a pregnancy would turn him into father of the year and the best guy in the world. Alot of us want to think that love will change everything and make things different. Like if he loved you, he would have given you a birthday you would have never forgotten. But it doesn't turn you into somebody you aren't. Love is shown through his interpretation of love, and this is what it has come to. I think you deserve better than that, even if you were physically abusive. I know it's difficult being on your own, but you have to be able to stand on your own two feet when it comes down to it. Are you in the position to have another child on your own income when you work full time? It's a two person job to raise a child. It's tough enough on the daughter that is already born isn't it?
I can certainly understand your panic. Kind of feels like the walls are closing in on you when you are so dependent on somebody and they aren't there anymore? Financially that is stressful enough. You can't make him come back, all you can do is let him be. Only then is he going to realize what he has lost and maybe want to be back. Not that I think his behavior is appropriate enough of somebody that wants to have a family with you. You can't help how you feel but this guy doesn't seem like what you want for your current life.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.