If you are studying to become a drug and alcohol counselor then you should know better than most what you are up against here.
The reason he talks about his past drinking specifically with pride like its a 'medal of honor" is because that is his history, that is what he has to talk about. You may talk about other experiences, and certainly he has had other experiences, but as a lifetime alcoholic his experiences revolved around, well, being drunk. He probably doesn't remember half his life.
When you love ANY guy you get caught up in their stuff. All people have "stuff", that's a part of all relationships. I don't see a way for you not to get caught up in it all.
You got some serious red flags here - multiple marriages, multiple rehabs, in sober living, and by your own account a dry drunk. Please pay attention to the flags - you have a daughter, do you need to bring this drama into both your lives? I get it that he is a nice guy but this is a MAJOR project.