Firstly you do not sound controlling at all and don’t let anyone (or him) make you feel like you are. You care about him and recognise that there is a problem. Has he admitted that he has a problem or does he just think it’s all fine?
I ask because when I first met my partner I knew he dabbled in cocaine but that’s all I thought it was and he told me he would give up when we got together. However he was doing it behind my back for a long time and I had no idea, I then found out and he said he would stop, fast forward a month and I found out he hadn’t stopped at all at which point he admitted he was an addict and couldn’t stop. His friends all seem to do it and despite me telling them they need to not do it around him and stop asking him to do it they haven’t so in the end he has blocked a few people and just won’t see them now (as far as I know).. the problem is he has to admit that he needs help himself and make these decisions himself. Until he does he won’t stop. Ultimately there is nothing that you can do unless he wants to stop.
I think sit him down and tell him straight that this is very difficult for you and you love and care about him but you can’t live like this, speak honestly and tell him how much of an effect it has on you because I think half the time they don’t actually realise. I’m not a professional obviously and there are people that you can speak to that can give you professional advice but as a fellow partner of an addict I just wanted to reach out and offer you some support. Please come on here and chat whenever you need to because it’s so important that you look after yourself x