I would get out of that situation, period. You have a son who is being harmed by
the abuse (just exposure to it is for anyone), and you have a heart problem, a HUGE
reason to get out and never look back.

He has the opportunity to take medications for it if he will. Since he won't he has no
one to blame but himself for his anger and inability to release it in healthy ways--not
at people--never at people, as he does.

Your heart condition may improve away from that environment.

Please take care of yourself and your son. That's enough to keep you busy and
happy.