My job is turning a mild medical problem into hell

Early in February I went to my job with a doctor's note saying I was required to sit. Seeing as my job has a position that is all sitting I didn't think this would be a problem. My HR department thought otherwise and called me two days later to inform me that I was now on medical leave, but no worries they would approve my States FMLA so I wouldn't be completely broke.

Well FMLA had different ideas. The first week I used all my accrued vacation and sick time to make ends meet as best I could. Now I'm close to six weeks unemployed, all my PTO is gone. I ironically can't afford meds I need to take care of the very thing I'm on leave for. I'm low on all general supplies and I don't have my follow-up appointment with the doctor until mid next week.

My job won't even add me back to the schedule until I have a note saying that I can return so even if I get a clean bill of health this week no telling when they'll actually schedule me to come back. I've had to ask a friend for a loan just so I can afford my antidepressants which I've been out of all month (which is certainly not helping how I feel).

I feel as though I'm being punished just because I'm actually taking my health seriously.