You may have to try the Dr. Expert Forum
But when that hot stuff comes up it burns and all sorts of muscle contractions take place causing all sorts of things to happen including sometimes closing off the airway and getting dizzy and/or in my daughters case Laryngospasms which try to prevent aspiration into the lungs .. the last time that happened some got in and she was on a nebulizer and steroids for over a month. All from an involuntary muscle contraction trying to keep the liquid out and was unsuccessful doing so.
The pressure on your diaphram most likely is from the gas pushing up .... it emulates feeling of airway constriction like asthma but none is involved.
I am not a Dr., just a mom a 3 refluxers.
You also may want to try the adult GERD board for more info. this is the pediatric but glad to help!