Facing breathing issues after covid.

I was covid positive on 10 May with mild symptoms. After a week i started experiencing breathing difficulty through nose but Oxygen levels were above 98. CRP, D- Dimer, CBC were all fine. I visited ENT doctor who told i have atopy and it has aggravated. She gave anti-allergic, nasal spray, anti-fungal, antibiotic, deriphyllin which I took for almost 9-10 days but symptoms persisted. Then i got nose X- Ray done and it was mostly fine with little inflammation. I got my ECG and Echo done and they are fine. It has been almost a month since i started feeling those symptoms but Still I feel i can't breathe effortlessly and sometimes my nosal passages are also not clear. I don't have any major cough or any phelgm or mucus coming out of nose or mouth. Sometimes i feel mild pain in my chest or stomach. Really don't know what's happening. Kindly advice.