Formerly salaried, now hourly for questioning authority

I am a recruiter on-site at an electronics co. in CA. I have always been considered an "exempt" employee as I hire, fire, interview, recruit, etc. Recently I asked my employer how it was legal for the company to override a state law and dock pay on exempt employees. They got back to me 2 days later and now made me a "non-exempt" employee. I now have to use the client's time clock and incidentally, I also saw a doctor for possible carpal tunnel. Ever since I questioned authority and filed a worker's comp. claim, I have been left out of meetings, constantly questioned about the hours on the timecard (which is electronic)denied days off (reduction in hours for everyone) but everyone else gets to choose their days but I was told only Tuesdays. I was told I couldn't go to a WC doctor appt and to reschedule.I was ordered to wear a headset even though it is uncomfortable because I ordered one. Constant petty things. I was even told by my boss that I made too much money! The list goes on. I feel they are retaliating against me for bringing up the fact that they couldn't dock my pay for leaving since I was an exempt employee. My boss and I do the same job. Her status has not changed. Also, I reluctantly signed a letter stating I could not sue them. I felt I had to otherwise I'd be fired (done in the previous year). Do I have grounds to file a claim with the EEOC?