Queen-gryla's journey

I've been working as a manager at my company for over a year and a half, but in the past three months, I've faced some serious health issues. The first incident was a severe health scare that led to sepsis and almost took my life, forcing me onto a leave of absence (LOA) without any paycheck, despite our policy claiming we have unlimited PTO and sick time. A month later, I ended up in the hospital again, but this time I was paid since it was before the mandatory LOA kicked in. Upon returning, I was unexpectedly put on final counseling for an incident I couldn't recall and wasn't given a chance to defend myself. I voiced my concerns to upper management, but they brushed me off. Recently, I was hospitalized again for a large DVT, which I delayed treating to avoid missing work. I informed my boss I would be back this weekend, but he seemed hesitant and mentioned needing to talk to upper management. When I checked in this morning about working today, he told me to come back on Monday instead. I have a strong feeling that something is going to happen on Monday, whether it's termination or being pushed to resign. My immediate boss seems to value my contributions, especially since I handle a lot of the workload, but his boss appears to have it out for me. I've noticed that he favors those who are more compliant and less challenging. I thought my efforts were finally being recognized, especially as my administrative skills have become apparent, but now I fear I'm on the chopping block. While I know discrimination is illegal and I could potentially build a case if they fire me, I really don't want to go down that road. I just want to be utilized effectively and not be stuck doing menial tasks. My coworkers appreciate my quick learning and willingness to speak up, but I feel like my confidence is being misinterpreted as arrogance. I'm at a loss about what to do next. Should I prepare for unemployment? I've put my health on the line for this job, and all I've received in return is punishment.