Man I feel this.
Last year, one of my son's presented with what appeared to be allergy type symptoms that would wake him in the middle of the night with an inability to breath. He's come crashing into my room gasping for air. Obviously, super scary and we had a few trips to the ER.
Those doctors kept prescribing inhalers and steroids, convinced it was asthma. Nothing worked.
After a couple months of this we were finally referred to a specialist at Stanford. Through process of elimination, lung studies, etc., the specialist determined that the cause was Protracted Bacterial Bronchitis and prescribed a strong antibiotic that my son needed to take for a month.
The assemblyline mentality in medicine completely missed it. After the month of medicine my son was better.