Being at a job you hate is one of the worst feelings, because you spend so much time there.
I took at $20,000 paycut to leave my last job and come to my current one, and I truly feel it was worth every single penny. Not everyone can afford to make that drastic of a sacrifice, but if you can make any sacrifice at all and not have it affect your ability to pay bills, then you owe it to yourself to make a change.
Seriously, DO NOT try and tough it out. It will not get any better. Find a way out immediately. Life is too short to spend 1/3rd of it in misery.