I had low energy a bit along the ME lines after covid+shingles and it's not really that it's not known to be a thing with doctors - they've all heard of it, but with no tests, treatment or known mechanisms there's not a lot they can do apart from maybe test for other stuff or hand out general things like vitamins/antidepressants/painkillers. We need greater scientific understanding of what is going on really.

I got tested for other stuff - low T which I thought it might be or prostate cancer which the doc thought but neither of those. I'm recovering a bit through normal passage of time.