I am having difficulty in breathing and my nose block suddenly ,i have no symptoms of covid eg fever cough,my spo2 shows 99 even after 15 min walk test,i have done hrct scan and it shows normal no lung involved,i tested my heart i done 2d echo and  ecg ,thyroid,d dimer,glucose every thing shows normal but my crp early was 25 and esr 71 then it went down to 14 and esr to 61, the problem has become less but when i think about breathing i get feeling that i am not able to breath and nose blocks don't know why?