I suggest reading all you can about alcoholism and attending an Al-anon meeting. This SR board also offers a wealth of info and experience from others.
You'll hear it's time to focus on yourself. Through working the steps you'll learn how to set boundaries and detach from the chaos and insanity of it all. Alcoholism is his problem to deal with. You didn't cause it, you can't control it, and you can't cure it. It's that simple.