After my Friday depletion workout (full body), I immediately drink a shake containing aprx. 120g sucrose, 100g whey protein mixed with cinnamon. About an hour after drinking the shake I get extremely tired, to the point where I'm about to fall asleep standing up. Is this hypoglycemia? Can anyone explain this rather scary phenomena?

I just ordered dextrose, I will start using that in place of sucrose. I'm just getting around to doing the carb up by the book.