Have you by chance been tested for achalasia? My Dad had it and his symptoms sound like what you described. I'm particularly interested because of its connection with nerve damage (which we know high blood sugars can do....) - it seems to me like the upper stomach problem of gastroparesis. From Mayo Clinic: Achalasia results from damage to nerves in the food tube (esophagus), preventing the esophagus from squeezing food into the stomach. It may be caused by an abnormal immune system response. Symptoms include a backflow of food in the throat (regurgitation), chest pain, and weight loss.