Most of the time, it's suggested to addicts that they not enter into any kind of new relationships until they have been sober for at least a year. There's a reason for this: Recovery is a full-time job.
I see red flags all over the place here -- and it sounds like you more want to take care of him (and help him change) than enter into an equal relationship between two adults. That's another big red flag for me.
As part of your training, have you undergone therapy yourself? I'm asking because a lot of people going into therapeutic professions have codependent tendencies. And if you don't work yourself out of those, you'll burn out in a month in that kind of job.