J, There will be times when the "adult" will rise to the surface. Those are the times that you will need to enjoy and then understand that he will pop back into the teenager mode. The periods of rational behavior are few and far between for a while.
You have an excellent support system and I'm glad to see others stepped in to assist you over the weekend. Your h will grow up, we just don't know when or how long it will take.
The movie has begun, but no one knows the ending....the only ending you have right now is to live your life to the fullest and leave the door ajar or as I always say, put a candle in the window and light it each night to guide him home. Be his lighthouse in the storm for he will need your light to guide him home.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
