My parents had covid in April and i tested negative but i did antibody test which was positive...since a month i feel when i exhale i immediately try to inhale and feel shortness of breath ..this happens randomly in day for few mins...i did my chest xray,2decho,tmt,ecg,vitd3 and b12 test. Vit d3 6.1/nu mg and b12 117 which is low.. Xray ,2d,ecg,tmt all are normal. But still sometime in day feel breath issue...what this could be...is this due to low vitamin...i am taking matilda forte,lumia 60k.. Also in past 2 month was very tensed ..pls suggest