This is hard, it was a simple choice for me to leave my job, but i can see your situation is a little different, but being happy is better than being miserable. Maybe start looking at a second place to work, and if something comes through, leave there respectfully, and see if that other job works out and so on, you could still maybe go back to this job if you leave the right way, but why stay if your boss is being unreasonable. This is a profession so i suspect is something you thought you would enjoy?