I'm not clear how only being in marriage counselling to be supportive of your AH would work?
From my experience of marriage counselling (limited) they ask you about your own family background and childhood so that they can get to understand what is "normal" for you both, and what sort of expectations you both have about what a marriage means - because it differs for different people, a marriage counsellor is there to help the 2 people in a relationship come to a better understanding of each other and fnd a way to be together that makes them both happy.
Marriage counselling doesn't work for addiction issues if they are the things that are troubling your marriage?