don't do that!

It is OK to fight! but remember only fight the battle you can win; this one is not! Whatever your boss had done won't get him a boots or demotion, don't be naive thinking your boss is going to change his personality.
Keep in mind, you just have a bad boss now, once HR involved, your boss will emerge as your worst enemy! your life will be even more miserable.
Move on! if there isn't opportunity and you still want to stay, be patient, wait for your chance to kill your enemy in one shoot! don't wake him up and get yourself in big trouble.