Most of what has helped me has already been mentioned, but there are a few things that have helped me that I don't see above:
1. Molybdenum for sulfite (and maybe acetaldehyde from candida?) issues. In any case it helps me concentrate.
2. Other b vitamins have helped with energy
at times. At one point I took fairly large doses of benfotiamine (a kind of B1) with nothing but good results. B2 is interesting for mood and sleep, but too much will deplete boron (and visa-versa...still trying to figure out if I can balance those two.)
3. Phosphatidylcholine: I also can't remember much of anything without this (or lecithin, which contains phosphatidylcholine).
4. Adenosylcobalamin: Helps me with energy and concentration. I think you'll find out more if you look of Freddd's protocol, so it is sort of already mentioned, but I thought I'd make it explicit.
5. Liposomal glutathione: Quite helpful at times, but not really noticeable other times. Worth a try, but I'd buy the other stuff first mainly because of the cost.
6. Chelation therapy: I have no idea if this helped, but it took me years to finish before I discovered all the methylation stuff. I'm glad I did, because I have to wonder what huge amounts of (in my case) mercury would do to an already messed-up biochemistry. Rich Van Konynenburg claimed that his "basic protocol" was fairly effective as these things go, and that in the cases where it was not he often knew of or suspected heavy metal poisoning. (Hopefully I got that mostly right; I am remembering it from the I think Sweden videos.) Rich Van Konynenburg died a few years ago.
7. CoQ-10: Forgot that one. Lump it with B-vitamins and stuff that helps the krebs cycle but can give insomnia in some cases.
Honestly, if you just got sick I would take a look at all of Rich Van Konynenburg's "
simplified methylation protocol." He claimed some success curing people who had recently come down with ME/CFS, and although it seems likely that other stuff out there could do this too, I don't know of any (non-toxic stuff) that has been studied. But I only know about so much.
There are other things that seem to have helped me (like vitamin K2, or all the anti-"ammonia" stuff) but as far as I can tell they are helpful in a more specific set of circumstances than those mentioned above. Also I take a whole lot of stuff to sleep, but you didn't mention that as a problem, so I left them out.
Best of luck in any case.