I have frequent sinus infections and have had surgery to help, which it did but only for a few months. Last year I lost most of my sense of smell and then I had a horrible bug that went on for months. I lost all sense of smell and could only taste sweet, sour, salt etc. I was extremely depressed as my sense of taste and smell was always acute.
I am shielded at the moment and the underlying condition that is the reason for it had worsened. A change of medication and an increased dose of another has brought my sense of smell back. It is such bliss to be able to smell everything, even not so nice smells. I don't take the loss of this sense lightly. I hope you recover yours. Covid19 wasn't about when I was struggling