Diane, I'm glad that you are back, my friend, but so sorry for all the stress and problems. I do agree with Ann that unfortunately older people can be as vulnerable as children and I feel very protective about them. It is probably best to break the news to them so they don't face a horrible surprise.
I know it is very difficult to not listen when your son tells you things, but these confessions are making you ill. Perhaps it be better going forward if you tell him you do not want to hear about his problems and hang up or walk away if he starts to talk about anything you do not want to hear. Eventually it will sink in and he will stop treating you in this way. You can't control his actions, but you can control allowing him to make you his confidante.
Sending hugs and prayers for all of you.