When he'd call me to yell at me for hours -- literally-- at a time, I chalked it up to stress and anxiety over his program.
This is absolutely, positively, NOT normal. He has some very serious issues. You mentioned PTSD, between that and the hours of yelling and the threat of physical violence it just all adds up to a person with a significant mental illness. I just don't know if there's anything you can do until that's addressed. My recommendation to you would be to go dark- no contact whatsoever. Right now he blames you for every problem in his life, if you stay dark for a while he'll eventually figure out that even though you're not there, the problems still are. Then he may figure out that he's the problem, not you. If he ever requests to reconcile I'd make it contingent upon him seeking professional help.
