Yeah - it sounds like he is an expert at feeling sorry for himself and attempting to get others to buy into his sob story. Sounds like an addict, to me. Just get your mind really clear about what he's doing. He is using you. And he's an addict/acoholic.
All you have to do is be clear - write it down if you need to - and the rest is easy. You do not need to let him take advantage of your family, you do not need to make it easy for him to drink. You have your own life to live and he needs to get out of your life and into his.
I'm pulling for you.