1) Check your iodine levels and correct if low. 2) Check your thyroid levels.
3). For long term covid in my personal experience and with others too, take 12.5 mg iodine until you feel better (possibly as soon as in 5 days) then take for three weeks longer. At the same time take 2-500 mg l-lysine pills. Do not drink coffee during this time. Covid and other viruses reside in your central nervous system permanently. Taking the lysine and iodine puts the virus into remission.