If your employer/boss is treating you unfairly, you should consider doing the following:
(1) DOCUMENT what is going on. Keep a journal with names & dates & descriptions of what occurred. Save copies of important documents and witness statements. If you make complaints, make them in writing/email and save a copy (expect that management or HR will later “not recall” the spoken complaints you made).
(2) COMMUNICATE SMARTLY. Before communicating, consider the potential risk of retaliation versus the potential benefit of communicating about your problem. Communicate politely to a reasonable person who could make a difference. Do not gossip. Do not march up to your harassing boss and lecture him or her about your rightness.
(3) PROACTIVELY ARRANGE FOR “PLAN B.” Apply for new jobs or otherwise make arrangements to cushion any blows that you can see coming.
(4) DON’T “RESIGN” OR SIGN ANYTHING IF PRESSURED TO DO SO. If your employer tries to force you to resign, you should strongly consider NOT doing so. If you resign your job, that may eliminate your chances to receive unemployment benefits, and may hurt your ability to bring several legal claims. If the employer pressures you to sign a resignation notice (especially one that includes a statement “admitting” severe misconduct), this is often NOT in your interest, and the employer will often fire you anyway, despite their claims to the contrary. If you are asked to resign and presented with a severance agreement, the terms of that severance may or may not be worth signing. But the employer should allow you some time to review the severance agreement (or to review any document for that matter) before asking you to sign it.
I get several phone calls a day from fired employees who didn’t do the things above. And I can’t blame them- these tips require anticipating bad behavior from others, which is something that good people do not like to do. However, when you are being treated unfairly, it is important you assess and address the situation proactively. Taking the ounce-of-prevention approaches above can reduce the risks of harms and help prepare for a legal claim in case it ever comes to that.
Please note this post does not provide legal advice- if you want legal advice, you should contact an attorney and discuss your specific circumstances. If you are interested in legal assistance from attorney-author Michael Brown or his law firm DVG Law Partner for your matter, please contact them here:
WI Employee Rights Lawyer: Severance, Wages, Job Termination, Discrimination 
Isnt it wrong for a boss to call you stupid and never appraise you for the good things you do
Yes, that is most certainly wrong. Unfortunately, it is probably not illegal.
In most States, there is no legal protection against bosses who exhibit abusive behavior. (There are some exceptions: you could have a legal claim if your State has an “anti-bullying” law, or if your boss’s abuse is motivated by a discriminatory basis such as your age or gender).
Often, the best solution is not a legal action, but rather to find a better job.