I tried relationship therapy with my exAH (whilst we were together), we only made 5 appointments, attended 2, because ex cancelled the others, and at that point I gave up. I didn't find it helpful, I was unable to open up, I knew ex would use anything I shared against me (and I was right, the few things I did impart have been thrown back in my face ever since). Ex dominated the conversation, saying all the "right" things, but none of it squared with his behaviour when not in therapy and some of it was down-right lies.
later (years later - and when I was still with him) I went to see a counsellor, primarily to deal with my increasing social phobia and anxiety, BUT I chose her from a list sent to me by my local Drug and Alcohol service, she used lots of different techniques, lectured at the local university (so I could check out her papers and credentials) and had worked with addiction.
I turned up telling her my Husband was an alcoholic, but I didn't want to talk to her about that, just my anxiety issues. She was fab, we really clicked, and she helped me enormously, as I sorted through my feelings, what was happening at home (and yes, ex's alcoholism!).
I also tried al-anon, for more than 6 sessions, the people were lovely, warm, non-judgemental, but I didn't find the messages there particularly helpful. Others have had a vastly different experience, and found it wonderful.