M.P.
Sounds like your blood sugar gets low and your body reacts. That sounds like hypoglycemia to me but I'm not a doctor. I know that when my blood sugar gets that low I feel shaky. Sometimes eating something helps and sometimes it doesn't.
I do not have hypoglycemia. I'm borderline diabetic although my last fasting blood glucose was normal. Perhaps there are other pointers to hypoglycemia. I have a meter and for awhile took readings every 3-4 hours and wrote down the numbers to see if I could see a pattern. I couldn't. I did learn that I need those mid afternoon snacks.
I suggest that you treat yourself as if you're hypoglycemic. Eat protein every 3 hours or so. Protein stays in your system longer. Be sure your meals are high in protein. General guideline is to eat 3 meals/day evenly spaced and 3 snacks/day. Breakfast/snack/lunch/snack/dinner/snack before bed. And all snacks should be protein.