Can I sue my employer for discrimination and emotional distress due to his behavior towards me?

Generally speaking, employers may harass and cause emotional distress to their employees. The only exception is that they may not discriminate or harass on the basis of race, religion, age over 40, sex, or disability under federal law; Washington State adds several other categories which are protected, of which only one seems like it may be relevant to your situation: national origin. If you believe you are suffering harassment due to one of these classifications, you could file a complaint with your state's Human Rights Commission or else meet with an attorney about possibly filing a lawsuit. (Note: when there is illegal discrimination, the employee may be able to win attorney's fees, so he or she would not have to pay for a lawyer; since many attorneys provide a free initial consultation to discuss a case, it would be worthwhile to meet with a lawyer and discuss this possibility.)

If you want to file a complaint with the state, here's a website that may be helpful: http://www.hum.wa.gov/ComplaintProcess/Index.html