Loving someone for their potential, or for what they are "partially" is not a good foundation for a marriage. Right now, the person you are living with is exactly the person he is willing to be, until HE decides otherwise and takes *action* to make changes happen.
I know you want to do what's right, perhaps by the standards of society or perhaps by your own internal moral standard. I would however encourage you to listen to your instincts. They are trying to tell you something. Right now, today, you're done. You want out.
So get out. You have an infant to care for, and you don't want this child growing up to think that alcoholism is a normal thing.
In a year or two, perhaps your AH will have changed and you can consider reconciliation. If it's meant to happen between you two, it'll happen. But right now, today, it's not happening.
I know how you feel...I also left an AH when I had a nursing infant to care for...my daughter was 15 months old. So, I truly empathize with you.