My DD swore by Tylenol Sinus when she had a bad sinus infection recently. (And we’re not big Tylenol people.)
DH always used a Neti Pot but there was some literature recently that advised caution when using them. You can use saline wash spray instead (if you’re worried about it).
Agree with humidification.
Covid can do funny things and cause funny sensations. One of the reasons people lose their sense of taste and smell is because it can affect nerves in the head, but for most people those types of things subside after a month or so. Just saying that could be part of the sensations you’re having, especially if no fever or anything like that that often comes with a sinus infection. I hope you feel better soon.