Have your iron and ferritin checked. Apparently Covid targets either the red blood cells or maybe the bone marrow, where they're made. Once I went on an iron supplement (Ferrous sulphate, 325-mg) I began to see an improvement (after a couple of months). You could also have your thyroid checked but the breakage makes me think that it's probably iron, I wouldn't put my hair in a ponytail unless you're using a scrunchy. The other thing is don't wash your hair too often, twice per week is enough. You could also bump up the vitamins that you take that will improve hair condition, such as biotin, B5, magnesium and zinc. Add collagen to your diet, it's good for hair. I make bone broth but there's also powdered collagen available (it's tasteless and can be added to whatever you're drinking). Diatomaceous Earth (silica) is also good for the hair. Good luck—it takes a while but it will most likely improve (from my experience).