“Head congestion lingering a month after cold”

I got the Flu vaccine at the end of Oct. then 3 days later came down with what I think was a cold, no fever over 99.6, but had runny nose, sore throat, sneezing. Covid tests done 3 days apart after symptoms began were negative. I have since lost taste/smell. All other symptoms except head congestion have gone. I had dentist appt. on Nov. 23 for regular cleaning/checkup at which time I had a white bump on my lower gum near a tooth that has a crown. Dentist said this is an abscess and I have an infection in that tooth. He prescribed Amoxicillin, a 7 day course. I took those immediately for the course of 1 week to keep that infection from spreading. The antibiotic did not clear my head so I don't believe I have a bacterial infection. I had a root canal done on the infected tooth on Dec. 6, the bump has drained and cleared and no issues with the tooth as of this time. I thought my taste/smell would return and my head feel clear after the dental issue was resolved but it still persists. I can't get an appt. with regular doctor until Jan. 3. Teledoc prescribed allergy medicine and nasal spray which I do not like to use as it gives me a headache. I do not have allergies although I'm sensitive to pollen/grasses during the spring season. Any info or advice you can offer would be appreciated. Thank you. Also need to mention that the dentist who did root canal prescribed Clindamycin but told me not to take it unless I had swelling in the days after so I have not taken any of that.