I understand when you say you don't want to leave him hanging, but he is a grown man and responsible for his own actions. Believe me he knows he is screwing up everything by drinking but is choosing to continue.
You can't make him quit no matter how much you love him. He, alone, has to want to quit and until that day comes he will continue to drink. It may take a week, a month, a year, or never. There is no way to know. That is why you have to do what is right for you.
Just my 2 cents