Earlier quoted context omitted.
Another one here (Woman, 24 y.o.). Contracted COVID, had a terrible three-weeks of infection. Nine months later, I am having weekly heart palpitations, I'm constantly fatigued and fogged in the mind and my lung capacity is half what it used to be - I now require an inhaler to go on my runs. I know several women my age experiencing far worse. Long COVID should not be ignored.
I hope this is taken the right way, but have you tried "vitamins" (broadly speaking)? Some I have seen with specific effects: Niacin, Black Seed Oil (Nigella Sativa), Magnesium megadoses, etc. etc. Don't dismiss these as "quack medicines", I've recovered from severe chronic illness thanks to some of these... I could expand if people ask, but really it's quite easy, especially for the HN crowd, to level-up rapidly on…
I have used said supplements before. In fact, I have a close friend who is very enamored with supplements and has about 50 different pill bottles in his medicine drawer.
Out of curiosity, I once spent two weeks taking about 25 pills a day at his recommendation, and I'm afraid they did not do very much for me — at least that I could noticeably discern.
The only supplement/herbal medicine I've had success with is St. Johns Wort, but I've been strongly discouraged from using it by a psychiatrist who emphatically emphasized that an SSRI is a much safer and more controllable way to achieve the same effects if need be.
Magnesium deficiency is relatively common, though I wonder if that isn't more of a dietary issue.