Welcome!
You didn't say if he lived with you or not. My son is going to prison (felony DUI) and I have gotten info about half-way/sober living houses.
I will bet that some sort of treatment is part of his parole...as well as urine testing.
Ask your BF what HE plans to do...determine what is his and what is yours and go from there. In reality what he does is ALL his so keep that in mind.
Regarding my son I have taken a hands off approach...my fear is that if I help and somehow make it possible for him to drive I couldn't live with it if he killed or hurt someone. So I choose to do nothing. He knows my boundaries and he knows I love him...the rest belongs to him.
Hugs,
JT