They are never directed at me and they don't last long, yet he feels the need to rant over trivial things. He feels that I am not being supportive if I don't commiserate in his woes. It is starting to affect his job and our relationship. I'm afraid that most people do not get to see the good side of him, but only the overreacting beast who emerges in times of stress. I don't know how to help him or if I can.
Anger is often a leading symptom of depression, especially in men.
And it doesn't heal itself. And there are plenty of consulting psychologists who specialize in anger-management counseling. The problem, of course, is how to persuade the mountain to go to Muhammad. You love this man and you are the best authority on how to encourage a little introspection that might let him see the problem. First of all, read up on the subject of anger and its management.