So sorry for what brings you here to SR. We have a forum just for friends and family of substance abusers:
Friends and Family of Substance Abusers - SoberRecovery : Alcoholism Drug Addiction Help and Information
Lot of folks who are or who have been where you are.
Does he have to come home? My dad kicked me out of the house the minute he discovered I was using drugs. Your son probably has no where to go, but that doesn't mean you have to let this chaos into your home. YOUR HOME!
Again, sorry for your suffering.