What is going on with me, can someone give a little insight?

I was diagnosed with bronchitis last month and have taken antibiotics for it. But every since then, I have had an occasional cough that resulted in my throat feeling like it closes up, and I struggle to breathe for a couple of seconds. I've been to the E.R. twice for it, and explained my situation exactly. But I've been told my lungs are clear, my EKG and blood tests are fine, etc. I've been thrown so many drugs, including: antibiotics, steroids, inhaler, Xanax, Flonase, and I've also taken allergy pills and mucinex. Nothing works. The cough is dry all day, but at night is when I notice mucus build-up. I know of two other people who have the same as me: My boyfriend and a friend of his. Is there something immediate that comes to mind that could explain what's going on? I'm tired of going to doctors and not having an explination. Thanks!