He's acting out like a child trying to get back at his mother. If there were seats elsewhere there and he didn't take one of them, it was because he wanted a reaction from you. He wanted you to say something to him. You didn't give him that satisfaction and I'm glad you moved. I really could throttle him for his behavior.
You are doing great. Don't let him see you sweat. Treat him just as you would a child lying on the floor stomping his feet because he can't get his way. Ignore him! He'll get over that little tantrum when he sees you aren't reacting.
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.