How long did you guys experience PEM after COVID?

Post-Exertional Malaise (PEM) was one of the first symptoms I showed when I first got COVID back in February. More specifically, February 6th is when I first noticed that I wasn't sleeping well at night and started to have heart palpitations. It fluctuated between better and worse until February 10th when I didn't sleep at all, followed by a cough, loss of taste/appetite, and chest pains. I went to the doctor on the 12th and I got diagnosed with COVID. I was told to rest and, for a while, my sleep got significantly better, my heart palpitations stopped, and my appetite came back. For two weeks I was doing good and on February 24th my cough completely went away. I thought this was a good sign that I was fully recovered and foolishly started working out again. Almost immediately that same night I couldn't sleep, and since I've had difficulties sleeping every other day. I've lost my appetite and my heart palpitations have returned.

Is this PEM? If it is, what can I do about it? Do I just rest and hope that I don't do anything to trigger it again? How long does it last? I start work again towards the end of this month and now I'm terrified that I won't even be able to do my job without triggering PEM. Someone with any knowledge or advise on this subject PLEASE tell me if there's anything I can do?