Personally, I believe what he has told you, he is who he is and he has made it clear that he will continue to use.
I am sure there is a way to work out the finances, he is blowing his money on drugs, so,
I cannot see how he could be that much help in that area. I would open my own accounts, in my name only and not give him any access to the accounts. I would no longer give him any money for anything. If you need to start selling off some of the joint assets, then do so.
IMO, comingling funds when involved with an active or newly recovering user is a real bad move.
Read the stickeys at the top of this forum, cynical one's blogs and Codependent No More by
Melodie Beattie.
Keep posting, it will help.