I am wondering if you have SILENT REFLUX……Xanax is helpful and can diminish the feeling of shortness of breath, but at the same time - it can depress breathing. One way to test if you have silent reflux, is to take a PPI (Proton Pump Inhibitor) 30-40 minutes before eating a meal - and then see if your sob improves. Sometimes it takes doing this a couple of times. Talk to your doctor about this. This happens to me sometimes…….my neck can actually start to feel tight after a meal - not every time - which tells me that stomach acid has made it’s way to my esophagus and lungs…….which can cause shortness of breath - and over time lead to asthma.