I agree with Sally - probably a combination of low blood sugar and dehydration. Way back, before I found out (officially) that I had low blood sugar issues, I would have episodes like you described. I didn't get the stomach pains, but that would go along with hunger. You said you improved after a little food and drink. I usually have some nuts or a granola bar with me in case I'm going to be late for lunch/dinner. Low blood sugar can be affected by a lot of factors besides simply not eating.

I think LDN leaves your system pretty quickly, so any ill effects would probably have happenned sooner.

I hope you figure it out - those feelings can be scary!

C