This sort of lingering on effect in seemingly healthy people occurs sometimes with other usually moderate-at-worst respiratory diseases (which may well be other coronaviruses.)
I am fairly healthy, can and do sometimes spend entire afternoons (with some breaks) pushing a manual push-mower as much as 10 miles in 1 long afternoon. (I worked out what distance was actually involved in push mowing my Mom’s entire yard!) There might be some raking, too. This in my mid-60’s. I never smoked and do not have any chronic lung problems.
Yet, I had a cold almost 2 months ago (my entire family had the bug in varying degrees, tested for COVID-19 and came up negative), and I am STILL battling a sort of residual chest congestion and cough, with some shortness of breath on occasion. Every 2-3 years I get a particularly noteworthy case of this — I assume it’s due to one particular virus I am susceptible to and my immunity wears off.
I’d guess that if I do get it, COVID-19 might well give me a very hard time in this manner, despite my generally good health and endurance.
You may have nutritional deficiencies due to a malabsorption syndrome like celiac disease. At least that was the reason why I got severe colds for many years. My health improved dramatically after I went gluten free and began taking nutritional supplements.