Could there be an untreated underlying issue? Seems worth doing a thorough checkup to eliminate Lyme, Wilson's, Sjogren, Lupus, neurological issues like FTD, diabetes, mental illness, eg major depression. Maybe there is something like modafinil that can give you a boost (with a prescription of course).

There definitely is. Partially managed sleep disordered breathing is one, whatever's up with my gut is two, but healthcare where I live sucks. I wait for months just to be treated dismissively and told I need a shrink for daring to think there's something physiologically wrong with me.

Have you tried parasite cleanse? I’ve used veterinary dewormers to great effect. I’m also surprised no one has mention doing sinus rinses to clear their breathing problems.

I'm pretty sure you've already looked into this but I couldn't scroll past without dropping in my thoughts; feel free to ignore them. I'm dealing with similar problems as a post-covid sequelae, in my early 20s with debilitating problems and also having to get to the root cause myself as doctors are clueless. Have you had your gut microbiome tested (with zonulin + IgA + parasites, fungi and viruses)? If so, feel free to plug it into cfsremission.com to see if something pops out. Oral microbiome and health? SIBO test? Candida? Immunological check up? ANA? EBV or other latent viruses reactivation? Elimination diet / carnivore? You could also try FMT if all else fails (either expensive at a clinic or DIY at home). Good luck man, you're stronger than most of us.

I do want one actually, yeah. Much of my decline started after heavy antibiotics a few years back, and I've experienced temporary relief of some symptoms from antibiotics last year, but then they came back with a vengeance.

I'll be seeing a gasteologist who has published papers on FMT (most here haven't even heard of it), and if that fails, I'd definitely like to DIY.