Dear Cindy, I feel for you having to go back to work so soon. Being hospitalized in the ICU is exhausting and anxiety-producing. Having to go back to work so soon just magnifies that.
Does your company have a human resources department? Would it help to talk to them, especially if the person who ordered you back to work is not in personnel but instead is a direct boss?
Two other thoughts. A note from your doctor saying you need a medical leave might help.
Also helpful: printing out online information about Post ICU Syndrome and giving it to your boss. Most people have never heard of PICS and have no idea what it entails. If you give this to your boss, the boss has no excuse for holding you to the same performance standards as healthy people.
Also, giving the boss (and others at work) printed PICS info could help you build a court case in the future, should it come to that.
I consider PICS at least a temporary disability; it's illegal to discriminate against the disabled.
But I'm not an attorney so make of this info what you will.