You've already lost him man....not saying he cant get help or change at this point, but it needs to be by force...because the drugs have taken all his logic and rationality and im imagining his personality too, essentially his soul is lost to the pills. He's just putting up with everything your saying or doing( and trust me i understand your trying) day to day while constantly searching for that next high, and thats not gonna change if you keep enabling him even in the slightest bit. If I was you id completely separate myself from him and just wish for the best.