Hey and welcome to Healingwell!
I get almost the same way right after I eat something that im very sensitive/allergic to. For me, its heavy preservatives, SORBITOL, milk, and high doses of sugar/fat. I too get the very exhausted feeling, and then you feel kinda empty. and weird.
Anyway, try eliminating those foods, as those are triggers for alot of people. For a few days try eating a very bland diet, like eating alot of rice and bananas and yogurts. See what happens. Keep us posted! :)