I have the same question about your covid test results. Covid can have many strange and long lasting effects on health.. Some people it effects more than others and the different strains of it..
Your symptoms could be a mix of covid and headinjury after effects . It might take some time to sort those out . Much of your symptoms fit with what we had with delta covid..

Maybe try sinus homeopathics or sinus OTC even with clear testing .
Maybe look for info on vestibular work.
Possibly some trigger points are causing the face muscle pain. Those can be checked on your self easily. Pressure pointer.com has a chart and info on how to check.. Hands and fingers work fine for it .