It isn't the change that is so hard it is the "resistance" to the change. I think he uses more than you think , and he does abuse your son. He needs to leave. Two lawyers talked to me free. No ifs....buts....about it....He has illegal drugs in the house and is probably using daily....drinks alot because he doesn't remember....(blackout)......where he goes isn't your problem......who cares.....?......he is grown.....he can crash with his drinking buddies......protect your son......Alanon isn't intimidating.....you do not even have to talk. It will help you learn to put the focus on you and your son.