If I have two disabilites and my employer fires me because I have been out for a year recovering is it legal?

Two years ago at this time of the year I fell ice skating and landed on my head and had bleeding on my brain and caused permanent right frontal lobe damage and a dislocated right shoulder. I had seizure on the way to the hospital and went into a coma for nine days. I stayed there for 21 total days. After rehabing I went back to work in April. They knew of my issues but they didn't care. I was forced to work 75 and 68 hour weeks back to back with one day off. They never made any adjustments for my condition but kept expecting all my work to be done faster than possible with my condtion. They began harassing me verbally then proceeded to demote me. I have been out of work for over year due to four more shoulder dislocations and shoulder surgery in July. I had a three to six month rehab from that surgery. Now I was about to return to a different position at work but they have either resigned me or fired me eventhough I was on the deactivated list and wasn't costing them a spot.