Its been 6 days and I feel like I cant take a deep breath.  Im constantly trying to yawn to get air. No fever, but did have chills on one of the nights.  Other than that I feel fine.  I dont feel sick, I just cant breathe. Im healthy, no asthma.  Ive had a flu shot.  Its worse in the evenings.
Thanks for your question on Chat Doctor. I can understand your situation and problem. Breathlessness in the evening is seen mostly with cardiac disease or bronchitis. So better to consult doctor and get done 1. ECG 2. PUT (Pulmonary Function Test). ECG is needed to rule out cardiac cause. PFT is needed to rule out bronchitis. If both are normal then you are mostly having anxiety. Anxiety can also be the cause for evening breathlessness. So avoid stress and tension. Be relax and calm. Don't worry, you will be alright. First rule out cardiac and Pulmonary causes.