Seriously, it sounds like you are in one of those "abusive employer situations". My advice is to change "psychological tactics", and instead of letting yourself feel like you "are tied to the whipping post", just learn to relax and accept the fact that they may can you for not performing like a slave.

It's amazing how situations can change by changing your internal view of it. The next time he whips you, just turn to him and say "I'm working as hard as I can without affecting quality, and smile and say "the more you pressure me, the harder it is for me to concentrate on work". Then watch the steam come out of his ears. If he threatens to fire you, mention that you are the only one who understands what is going on in the code, and he will be set back 6 months if he fires you and has to hire someone else.

Of course start looking for another job; why should you get an ulcer because your bossman has dominance problems? By all rights, it's your boss who deserves the ulcer, so blow it back in his face.