I am sorry you are going through this. I understand this pain, as I took am going through divorce with my soon to be ex husband, heroin user as well. I am fortunate that he does not live in the house, its been over a month. Yes, it is very hard to detach and leave when he is in the house. Please maybe talk to your lawyer to see if he can evicted. I know you feel horrible doing it, but this is toxic. I didn't realize how toxic until my ex left (on his own accords for a binge run). Do everything in your power to remove him, he wont leave himself. Plus, if he is shooting, forget it, he is not a human right now, not someone you can agree and expect to follow through wtih.