It's a massive problem FarNorth. Two years on for me and many others in my long covid support group.
The medicos are flummoxed by it with many studies ongoing but no resolutions at the moment. It's such a mad assemblage of symptoms that I can't see it ever being treated formally, it's all DIY to see if anything works as Maybee's suggestion of probiotics.
It does help me when people share their experiences as it makes me feel less like I'm losing it. The fatigue and brain fog are the worst and also the feeling when, after a few good days when you think you're winning, the symptoms reoccur, it's so disheartening. I feel like I've aged 10 years in the last two!
Nanna8 you're so right when you say it's a foul illness. All we really can do is support each other.