Some years back I developed a chronic wet cough that was tricky to diagnose, and it tormented me for about two years. I even tried allergy shots to control it, but they didn’t help, though I gave them plenty of time to work. It was finally diagnosed as asthma, using an elaborate test called a methacholine challenge (that might be your “bong” test). This was for me the third leg of a three-condition syndrome called Samter’s Triad, or Aspirin Exacerbated Respiratory Disease, which includes asthma, sinus issues/nasal polyps, and aspirin hypersensitivity. I tried a wide variety of inhaled steroids, including Symbicort, but the first one that actually helped is one called Alvesco. I’ve been on Alvesco for 4 or 5 years now with good results, though my insurance company hates it and hassles me about it every year. My understanding is that the various inhalers have different particle sizes, and this can affect where in the respiratory tract they settle. Good luck finding a solution!