Could I sue for lost wages and my pension that I could loose if I do not return to work?

Ii have been an employee of the USPS for the last twenty five years or more. I worked daily with the same group of people. After being transferred to a larger location, the group that I worked with gossiped, bullied, and rallied with the other co-workers until I was made the outcast. I confessed to a supervisor that I used a substance that helped me with the daily stress. I was dismissed immeadiately and was forced to undergo counciling and seek treatment for substance abuse. I was most definitely the victim, but being labeled the trouble maker. The supervisors and the union reps are baseing everything on what they are being told rather then the true facts. I cannot ever go back and face the people who took advantage of my mental state and used it against me. I have records of seeking help from therapists, and also other people who are aware of the situation. The workplace was so unstable, we were all threatened to be killed by another employee. He did come..