If you don't pick him up, my guess is they will call Children and Youth Services and have him placed in the custody of the County/Town whatever where you live.
Then he'll probably go to some type of shelter or respite foster care home until they can figure out what to do with him.
Then, if you refuse to take him back (I'm not sure on legality and ramifications, or if you can really *do* that), they will probably take you and him to court, and either legally place him back home, or place him into some type of "theraputic" foster care where they will make the goal (more than likely) reunification, and you will work with them, foster parents and whoever else to bring him home.
Know, through all this, if it does go this route, you will be forced to continue insurance, and be prepared for hefty child support payments. I've gone this route (not refusing to take my son home, but placing him in custody) and it's financially drained me.
You could ask about emancipation, but I'm not sure about the age on that. I emancipated my son, but he had turned 17, was in legal trouble, and I refused to pay one more penny toward anything he was doing. I had just cause for it, and was lucky enough that he was already involved with court, so we just did it with probation/judge/court etc.
I'm very sorry for what you're going through.
