what rights do I have diagnosed with ms and being harrassed by employer?

diagnosed w/ms 7 yrs ago employer knew of diagnosis had mini stroke as well. He would yell & scream @ me on a daily basis which ended up in me crying almost on daily basis. He knew stress was a main cause of ms. He let 2 employees go & added more work to myself & other 2 girls in office. He threatened to take money out of our paychecks. We had no contract w/him he refused to put anything in writing & he changed rules in office almost on daily, weekly & monthly basis. I was pd salary, he cut my pay 2 yrs in a row 1st yr by 3000.00 & 2nd yr by 4000.00. He refuses to pay me my last check he says that I owe him money. I worked over 40 hours per wk, he cald me @ home to go into office to take claims for his friends & etc. I had some addtl ms symptoms occur, also had ms exasberations which caused me to miss work. I finally started looking for work found a couple of jobs, but when left work jobs didnt happen now unemployed & turned down for unemployment due to health reasons