I don't attend Al Anon. But I read lots, post on here and have a one to one counsellor to talk to. I highly recommend Melody Beatties 'Co-dependant No More'. I think it ought to be a primer for everyone living with/affect by someone in their lives who has problems with alcohol! Another book I found useful was 'Getting them Sober'.
I went to a local Al Anon meeting and it just wasn't for me. I much prefer the anonymity of online fourms. Al Anon has helped so many, it could help you too. But don't think that is your only option here.
The best way you can support your husband is to look after yourself. Sounds counter intuitive but its true! You've already said you're feeling like a basket case and you will be no use to anyone if you don't start to look after yourself. He's an adult and needs to be treated as one. Posters on the forum have said that you can literally kill an alcoholic with kindness. It sounds really selfish but you have to take care of you, first and foremost. You didn't cause his drinking, you can't control it and you certainly can't cure him. Harsh stuff I know. Take time to read through the stickies. Your story will be repeated in a lot of the threads there. When I read them for the first time I found it really spooky!