I have a question for you. Do you know forsure it is coming up from your chest or is it from your nose or drainage from your nose. I have had same issues. Thanks God mine is mostly only in my brain. About 5 months ago I was like you. I have had bronchitis 10 times before covid but it was all from my chest. Anyways 5 months ago I had what felt like something but it wasn't coming from my lungs. I went to walk in clinic. The doctor said it was drainage from my nose to throat. I tried to blow my nose, Nothing, Coughing nothing. He put me on antibiotics and steroids. Also did a chest xray. Also a nasal inhaler. It finally went away. I never before covid in 2020 had any allergies. Maybe this is a new thing I got from covid. The gift that keeps giving. Hope you get the help you deserve.