S,
I would recommend counseling for yourself before couples therapy. You need to figure out yourself before you add in another person's perspective.
Good for you for recognizing nothing has changed in your marriage, Sober or drunk. It is the hardest thing In your life to do, meaning divorce. You need to take your time, reach out for therapy, alanon, open aa meetings, and sr. Do your homework. You owe it to you and your child to make sure that you are making the correct decisions in the right frame of mind. This is not a race, take your time so you have no regrets. Hugs my friend, it will be clear one day, just be patient.