Were you confirmed to have Covid? Because February 2020 I got the same thing, was coughing for a month straight and was miserable. I thought it was Covid (there was no real testing at the time) but in December I got legit Covid and had zero coughing symptoms, just felt like a mild flu and my taste buds stopped working.

I concluded after some research that what I had earlier in the year was a sinus infection exacerbated by seasonal allergies.