Can I be fired after given 2 week notice

Just returned back to work after off for 4 months due to illness, was given my evaluation, Was told that I don't follow orders, when ask for an example, she was unable to provide. Ask if I could return to my previous schedule, was told by out going manger that I need to talk to Stacy, week went by, ask about my schedule, was told had to do what was best for unit, on same day, was getting a patient, did not hear where charge nurse (Stacy) told me to put patient, (Patient was put in bay that I was assigned, (not a busy day) Stacy came and told me that I need to put patient in next bay, incase nurse next to me would get another pt, I stated that didn't hear her and if need be I can move over to next bay. I was told by supervisor, "that I can put my f**king pt any wheres I f**king want", I never said that.
was called in, turned in my resignation the next day, told supervisor
that I had a target on my back and they were out to get me, she stated "I'm glad you recognize that" she advise me not to return to unit that she would pay me for my two weeks and if I could find and internal job that be OK. Received
my separation papers on Wednesday, March 7th Terminated/fired for not following company policies.
What can I do if any thing?
Thanks