No where to turn.....

I work in a small hospital that is a sister facility to a larger hospital 4o miles away. I transfered to a new department in Oct. after being employed in my previous department for 2 1/2 years. I became ill in January with recurrent bouts of chest pain. I had been admitted to the hospital once already. After being admitted again, my supervisor came into my hospital room to infrom me that I would have to change my employment status to 'as needed' or transfer back to my previous department because she was tired of covering my shift for me. At this time I had been up all night in the emergency room,then transfered to the telemetry unit with a cardiac monitor and a morphine pump.
She in effect dump this in my lap, told me to make a decision and walked out. I had just been told by my doctor that I was being transfered to a Heart Hospital for an Angiogram later in the day. I became very upset by her news and started crying. My chest pain came back. My nurse called my doctor to get me something to help me calm down and to help alleviate the pain. He wasnt happy with the fact that my supervisor upset me. Apparently(according to him, later) he had 'words' with my supervisor.
I was out on medical leave for 2 weeks, then my mother got very ill and passed away. I was out an additional two weeks for that.(FMLA)
3 days ago smy supervisor presented me with my 90 evaluation ( 2 months late).
With the evaluation, she had included a letter outlining the incident in my hospital room and blamed me for her entire converstion with my doctor.
Accused me of becoming hysterical and calling him to get back at her.
She went on to accuse me of excessive absences and an inability to deal with stress.
When asked to sign these documents I refused. She said in refusing to sign I could be terminated. I threw the papers on her desk and said " well I guess I dont work here anymore" and walked out. The administrator agreed to sit down with us and try to work it out. When I returned 2 days later they had destroyed the letter and changed my evaluation totally. I tried to get my job back and was told that I had verbally resigned. The reason I resigned had been destroyed. I dont understand how somwething like this can happen. I was the victim and I am without a job now.