I have reactive hypoglycemia. That means that after I eat, my body releases too much insulin. Your description of hypoglycemia is very familiar to me. It happened to me several times a day for about a year before I figured out how to trick my body into releasing less insulin, by eating a high-protein, high-fat diet, and never eating anything with any starch or sugar until I've had protein first. That mostly controls it, but I still have some issues sometimes, especially after lunch.
--Leigh