I have found joint pain comes and goes (wrists and ankles and used to be elbows for me) with restricted diet (now on Leo Galland’s MASC diet, see histamine diet and long covid in his 52 page word doc on website for treating long covid). I am much much better on this diet across the board, and have gained stamina (had PEM). I think I added a supplement from his suggestions that aggravated my wrist pain recently (so now back to adding them three at a time to speed the process), and still have brain fog, but getting better.