Yeah the chronic health problem is one of the issues they won't bring up. They can tell it exists through your health insurance costs.

When I got sick at work and ended up on short-term disability they used my sick days against me by losing my doctor's excuse notes.

I would not get invited to meetings about projects and they would all vote for me to do the project. Never giving me the meeting notes or any documentation on the project. So I would ask coworkers who were at the meetings for the notes and they would answer back "I don't know" for any question I asked. So I had to do the projects without any information or notes or documentation and they got mad that I didn't follow the notes in the meetings.

They did it on purpose to get rid of me, just like they are trying to get rid of you.

You don't say if any/all of these issues were brought up previously in a less formal context, like a basic face-to-face meeting. If they weren't, that smacks of unfairness.