If I had that issue, I might consider channeling that rage into something like martial arts. Break a board or something 
When I lived in San Francisco, every morning in the park I saw a bunch of people doing tai chi. I’m not sure I’d have the patience for it, but it seems pretty meditative. I hear yoga is a favorite and i think I might give that a go. I REALLY think you should talk to your doctor about it, it must be pretty scary for you.
I have a brother who used to rage (at himself) and I think he uses jogging to release that energy. I don’t live near him anymore so I don’t know if its still helping or not. Every time I read your posts, I worry for you. I don’t know you so I don’t know if its something that can be controlled through meds or therapy, but is it possible you may have had some issues (parents not supportive? poor self-esteem?) possibly from childhood (in my brothers case, our mother died on his birthday), that maybe therapy could help you get to the root of.
Hope today is a good day for you. Next time you want to rage at yourself, think of you as a little boy who needs protecting and practice some self-love 