Fallgirl, He's definitely got depression going on, but it's more like the teenage son acting out at mom. He's doing a lot of what we would expect from teenagers. He's also attempting to push your buttons for a reaction. Don't give him one.
There's no need to call a doctor...you can't fix him...remember? He's got to be the one to do that. Now, if you get sucked into his drama full time, you'll definitely need to see someone. They are just plain nuts when they are going through the replay/depression stages. Drama is written all over him. The best thing to do is ignore his behavior and continue living your life and being there for your children. The less you react to his nonsense, the better.
Good luck!
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.
