@alexm1994- Welcome to Mayo Connect. My husband is like you, or you like him. Whenever something slows his workouts and he's ready to start up again he pushes like crazy- way too soon and too much. You probably should come back more slowly if you have taxed your lungs and thinking that you have had COVID then I would suggest being even slower than usual. If it was COVID then your lungs are probably very irritated.
https://www.mayoclinic.org/diseases-conditions/exercise-induced-asthma/symptoms-causes/syc-20372300
https://www.mayoclinic.org/departments-centers/pulmonary-function-laboratory/overview/ovc-20398545

If your symptoms do not improve I suggest seeing a pulmonologist for lung function tests. Were you ever tested for Covid-19?