If you haven’t already tried this I agree with what others have said about switching to natural soaps/deodorant/etc. Also, washing your hair daily will cause your scalp to produce more oil, it’s better to wash it every other day or even less if you can. It takes some time for it to “adapt” but if you can at least skip washing it on your days off (that’s what I do) or use dry shampoo there’s a chance it’ll be less oily after some time.

I’m not a doctor, just saying what works for me. Not covid related (I think I had it early on but I was lucky to have no long term issues - sorry you are…) I just have naturally kind of “difficult” skin and hair. I notice a definite improvement using more natural products (and I’m obsessive about my grooming routine so unlike others in this thread I’m not saying skip showering, etc… I don’t think that’s necessary.)

I wish you luck.