I wouldn't give up if I were you

Apparently, they have been bullying you for a while and they are abusing their powers. what you need to do , in my opinion, is to seek legal advices about anti-bully. If your case were occured outside US like Canada, it would be much easier to deal with. Even in the States, there must be a law which should protect you. I suggest that you google such information first. I also suggest that you go to your doctor if you have sleeping problem and headaches and tell you doctor you have been distressed by your boss.