would it help you if you made a conscience decision to force yourself to think about something other than him for a minute at a time. i mean, focus on something else. think about it this way, just for today. he has a license, he has id, if something happens to him, somebody will call you, if you don't hear anything then he must be ok, maybe still using somehow.
i think that sometimes my rah would make that one phone call just to see what frame of mind i was in, to see if he still had a home, and if he detected that i was kind of ok, then he didn't worry about coming or calling for a little longer. i'm sorry faith, he's doing this cause he thinks that he can continue to get away with it. as long as he has someone to pick him up when he's down, he has a warm landing pad, food and all the other nessessities of life, he's more able to supply his own drug habit, why would he want to stop. he's an addict. maybe it time for you to step aside a little bit and allow him to reach his rock bottom. that maybe the only way that he'll have a chance to get sick enough for him to want to seek help.
i know it hard to do, but what if you could look at whatever decision you make, like you only have to do it for one day. sometimes when we think like way off into the future, it makes it so much harder to do. try to stay in the day that you're in, and only think about tomorrow when it comes, knowing that you can, if you want, always change your mind. might make things a little easier for ya. he's not gonna call or come until he's ready and there is nothing you can do, but what you know you need to do to keep this behavior from continuly effecting you like you said. whatever you do, don't have to be forever, unless you want it to.
i had to make myself not think about what my husband was doing or who with, only made me sicker. hope this helps a little.