I'm so sorry it has come to this, but it sounds like you've made your decision and you will be at peace soon. I quit the job I was working at when I was diagnosed with Graves. We think that job had a lot to do with developing Graves (since I have no family history). My bosses were supportive for the first week but then they went right back to making fun of my tremors, brain fog, weight fluctuations, etc. I took a long weekend and decided I was quitting. I had saved up enough to live for three months without a job, but fortunately, I landed my dream job after six weeks. It made a world of a difference. I went from working at a PR agency to working PR in a hospital, and finally my medical issues were no big deal in comparison to my co-workers colorectal cancer and of course, our patients.
I firmly believe a healthy, supportive environment plays a huge role in how we handle medical problems, treatments, and subsequent recoveries. That environment is 24/7. So not only did I eliminate an unhealthy 9-5, but I broke up with my long-term but unfaithful boyfriend, I stopped associating with “friends” who cared about nothing but going out and getting blackout drunk, and I even took a little hiatus from my recently divorced parents, who focused more on trash-talking each other than worrying about their sick daughter who was 1,200 miles away and completely alone (I am on great terms with them three years later).
Women are awful to each other, especially at work. I left my dream job in February to move back to Massachusetts where I could be with family and friends again, and also getting my eye surgeries done. I am working a job (higher ed) that is not as bad as the agency, but creates immense stress. I did not hear from my co-workers once during my two-week recovery from OD. They don't realize how big a deal TED or Graves are, and while I love working in healthcare for other reasons, most people don't work in that industry unless they care about others.
I think you're doing the right thing. I'm not sure what you do, but maybe you could find a freelance, part-time, consulting job? Or maybe you can find a healthy environment still doing what you love? I was extremely worried about developing double vision after OD, and knew my job was at-risk because of it (I don't qualify for FMLA since I haven't been there a year yet), but my health always comes first. I'll need eyelid surgery in a few months and possibly one additional surgery, but now I can focus on finding a new job knowing that the worst of TED is behind me. I hope you're there soon, too.
On a side note, while getting into an emotional, heated discussion with corporate may not be wise, I'd consider sending them a letter letting them know you liked your job (if you did) but that the company might retain good employees longer if management curbed the unprofessional acts and attitudes related to yours and others' health, which is actually none of your co-workers' business!