I have been harrassed at work for several years always being accused and them disciplined I was suspended for supposedly being rude to a pizza delivery guy, suspended for two weeks. Thr last incident I was accused of listening through a wall to the manage

A co-worker accused me of listening to the office next to me. I wear hearing aids and couldn't hear if I tried this made my job want to fire me. They gave me three choices have a hearing and get fired sp the hearing would be useless just going through the motions. Quity job which wasn't going to happen or get laid off which I took. I have a union but as I said I got in trouble for supposedly speaking rude to a pizza delivery guy and they made me sign a last chance agreement anf waive my union representation. I had np idea what o signed and asked my union steward to have their lawyer lawyer look at it and was told several times nobody got back to him which I think is bullshit. Can I sue