Try keeping track of everything you eat and see if there's a pattern. Pay attention to how much your drinking every day, being chronically dehydrated can have a wide range of side effects. In the morning try soda crackers and ginger ale. How long does it take to pass in the morning? Is it always the same or does it very?
See a gastroenterologist. It's possible that you have GERD, or acid reflux. I suffered the exact same symotioms for years and finally a gastroenterologist put me on protonix and zofran (miracle drug for nausea, commonly used w chemo patients ) and once my GERD was under control the nausea subsided. I never realized I even had Gerd as I rarely got heartburn, however I did get a raspy voice, coughed/cleared my throat often, felt fullness, etc.
I wish you luck!
Please see my last post. I didn't realize I could tag you when I posted the reply. Good luck!