I can relate. I've never been an angry person, and the depth of anger over being betrayed was overwhelming.
To share a quote from another member that was working with me at the time:
"You aren't used to being angry, are you?"
To share a quote from my IC at that time:
"You aren't used to dealing with your own anger are you?"
It is so frustrating, but it is best that you get the anger out in the most constructive possible manner, versus turning it inwards.
Exercises I have done that have helped:
Writing lengthy diatribes that I never sent out, just to get it all out.
Venting privately to other members here.
Venting out on the boards.
Lots of physical activity.
Talking to my IC about how angry I was.
Talking to my wife about how angry I was.
So sorry for the pain you are going through. We're here for you, and the emotions you are going through are 100% normal and valid, as painful as they are. Hang in there.