Do I have a case if I was bullied at my job?

My job description did not include many things that I was asked/required to do. I was told once that I was like the peanuts character with a black cloud hanging over my head. I was put under so much pressure that I made mistakes. I was told that if it wasn't for her that I would not have the job, however she told another employee that she was going to terminate me 1 week prior to a write up threatening my job if I made one more mistake. I told the director about the remark about termination and the next day was the write up. She talked to me like I was dirt. I decided to retire due to the stress instead of a termination.