Hi and welcome!
Keep reading and posting. My ex boyfriend is an alcoholic. He quit drinking for two months. It was the best our relationship had ever been. It was a pink cloud. He relapsed and never looked back. I left.
Your ex should be commended for taking this stand to protect your child. Sometimes when we are on the outside looking in, we see far more than those in it.
Also, I realize you have been told there are no codependency issues in your relationship, but your post reads a bit different. Have you read "codependent no more" ?
Best if luck!