I had it. I looked it up and it's a thing.

For me it went away after the worst of the COVID symptoms but before I was all better.

I also realized that I was partly anxious because I was getting up to pee and million times a night so I couldn't rest and it just made me feel worse. Turns out the tea I was drinking had 3 ingredients that act as diuretics. Stopping that helped.

To be fair I had been anxious going into COVID but it was worse on COVID, improved and then got worse again without COVID to blame.