A related discussion,
Middle ear infection & heavy chest was started.
Acid reflux could still be causing your symptoms. It may be that the proton pump inhibitor (PPI) is not completely controlling your acid reflux. Another consideration is that asthma is causing your symptoms. Ask your doctor about being checked for these things.
i have a similar thing - very simple in my case. When I feel like It's hard to get a breath through my nose I do a mouth breath and it's easy. Basicall nasal congesting from allergies are making it harder for the air to get sucked down. It's quite scary at the time but I know I can mouth breath when required, and also I can treat the congestion/ allergies. a small does of antihistamine keep it at bay. Hope yours is as simple. Sometimes the simple things don't get picked up by the doctors and you go through enless tests and get worried because they can't find anything. Breathing problems can be very worrying and frightening and the stress can make it worse. good luck
have you looked into chronic bronquities?
I have been to see my doctor three different times. The first time he thought it might be Pneumonia or Bronchitis but I have no cough, no fever, no wheezing or phlegm. My lungs sound clear according to the doctor. The chest Xray and blood work came back normal. I just have restricted breathing. I must say the breathing part is getting much better but full inhales and exhales are tight and cause my restricted breathing to return for 30 minutes or so. It might go away after a few months but it is frustrating not to know what it is.