DO NOT GIVE UP! Keep searching for the answer. Don't leave anything unturned. Your body is not doing this for no reason. Something is not working right and you will find it out.
Ask every question....Is your cortisol extremely low (on the verge of Addisons), are your electrolytes way off? Did you get your heart closely looked at? Is there some severe candida thing going on? Are you on some medication that is having interaction with supplements or food? Very interesting that eating seems to bring on symptoms.
Turn it all upside down!
I'm serious...LOOK AT EVERYTHING! I'm sure you already are.
Keep posting here, I will keep thinking and maybe others can brainstorm and come up with an answer that will change things around.
Above all.....Don't worry ....You will figure this out!