He's an alcoholic. He put on a facade to get you into his life n now that you are there, he's showing you who he really is. That guy you met n fell in love with is a hostage to the bottle n now, you are too... unless you decide for yourself you don't want to be.
This is a life long disease. Is it manageable? Yes! But by him only! You must know, you can not n will not have any say in it and until you understand that, well... welcome to HELL!