When there are children involved or, as in this case, children you treat as if they are yours, no contact isn't completely possible. Then you have to ask yourself what the contact is about. Is it about the kids or really about him? There's nothing wrong with wishing him to get better but that's not your job anymore. He's an adult, he has to want this and take the steps needed. If you are subordinating your best interests to him, that is not healthy. You should read up on co-dependency and see if this sounds like you. Are the kids old enough to have smartphones and make some of their own choices? If so make sure they know they can always visit or text you as long as their Father is aware of where they are. I don't know if you have looked into any sort of counseling for yourself but I think you should. You are dealing with someone with no empathy and that is hard for a normal person to wrap their mind around when trying to figure out that person's actions and motivations.