Ok. There is a lot of steps here to fight. I have gone through it before and I am right now ( because I can’t work alone)
1) is your disability on your resume? That’s covers your ass.
Have you been honest about your diagnosis?
2) do you have a union?
3) how is your safety at work with your disability? Doctor note?
4) it could be a human rights violation for the employer.
5) company insurance company annoying you ?

I don’t know where you live so how the legal or human rights situation works. I’m in Canada 🇨🇦.
It is a legal matter if they want to fire you. FIGHT YOUR RIGHTS.

They didn't fire me. They asked an attorney to look into is it safe have someone with epilepsy as a disability employed. The attorney did some investigation and found that it would be safer to have me off of premises until they were done with their research. During the investigation, the business did job interviews to replace me. They hired somebody who was in a wheelchair so they will fill the hiring disability quota and i was let go because having someone employed with epilepsy is considered a high-risk.