I also have this problem. It really flares up after I eat or drink something. My gag reflex kicks in and at times I almost throw up. Mine started about 1 year into my COVID journey when I was diagnosed with low CO2 and sleep apnea and started a CPAP machine. I’ve tried mucinex (which helps a little). I’m now moving to Flonase because my nasal passages are very irritated. I’m also starting to use a nebulizer with saline solution to see if that helps. I’m seeing my ENT soon. I’ll update if I get results.