Welcome to Healing Well! Sorry it took so long for you to get a reply. It sounds as if you've got a lot of things going on with your upper GI tract. You seem to have stumped the medical profession. Have you had a barium swallow with different textured meals? That might provide some insight. There is also a stomach emptying test, so they can determine how long it takes for food to leave your stomach.
It sounds as if they're pretty confident that food just isn't moving along, and that's what's causing your problems. It does make sense to take a medication that helps with getting the food moving through.
Hopefully someone who is dealing with a similar problem will be by to share their experiences with you. Glad you've joined the forum. You're definitely in the right place. Keep us informed about what you find out. Good luck!