I was just in this exact same position last year, and unfortunately have had this experience earlier before that as well. First, the situation may stay the same

I was just in this exact same position last year, and unfortunately have had this experience earlier before that as well. First, the situation may stay the same or worsen, but it won't get better, so you should begin looking for a new job. Second, don't talk to HR or make any formal complaints. Talking to HR makes it worst - they are there to keep the company free of trouble and liability, not to make your workplace better. Chances are if you talk to HR, they will tell your boss and everyone will start picking on you even more in an attempt to get you to quit. Talk to a lawyer to determine what type of documentation and evidence you need to take legal action, and get it. In the meantime smile and act like everything is fine at work. The most difficult part of this will be finding a competent lawyer who can help you stick up for your rights. It's a bad situation, but good luck.