Good evening and thank you for entrusting me to assist you. I am very sorry to hear about the way you are being treated.
First, to clarify, it is not illegal to be generally rude, disrespectful or bad at management. The law does not impose a general "civility code" in private sector employment. What is illegal, and the only way you will have any claim against your employer, is if you can prove that you suffered adverse employment action because of your ethnicity, or if you can prove that you suffered harassment motivated by your ethnicity that was "severe or persuasive" and caused you to suffer emotional distress. Note, it is the employer's motivation that matters.
Unless the harassment you have experienced up to this point has been so severe as to manifest into physical symptoms (i.e. panic attacks or clinically diagnosed depression), it would typically be prudent to wait until you suffer actual adverse employment action before initiating any sort of legal claim. This is because at this point all you have is a claim for emotional distress, and such a claim will not be valuable unless you can demonstrate truly severe emotional harm.
If/when you are terminated, your first step will be to file a complaint with the Department fo Fair Employment & Housing. The DFEH will investigate and attempt to mediate a resolution with your employer. That not forthcoming, they will either file a lawsuit on your behalf or issue you a "right to sue" letter, which will enable you to sue in civil court with the assistance of an attorney.
In the mean time, you want to carefully document any and all instances of what you believe to be ethnically motivated harassment or unfair management, as this will help you create the necessary body of evidence to prevail on a claim for discrimination/harassment.
I hope that you find this information helpful. Please do not hesitate to let me know if you have any questions or concerns regarding the above and I will be more than happy to assist you further.
If you do not require any further assistance, please be so kind as to provide a positive rating of my service so that I may receive credit for assisting you. Very best wishes moving forward.