Why would you go to an AA meeting? That's his deal. Are you an alcoholic? It's not supportive to go with him. I promise it's not. Being thoughtful of the process, detaching so that you can take care of yourself and your child, and leaving him to his own recovery journey is supportive and loving.
So, he goes to AA. You go to Alanon.. it'll be really helpful.
His recovery is not dependent or contingent on you or any decisions you make, support you provide, or role you try to play in it. He has to want it more than anything else, more than your marriage, more than your family.