Thanks for using the forum.
The only way to know for sure is to have your blood sugar tested. I would recommend speaking with your doctor about your symptoms. If your blood sugar is elevated, you are going to have to make some dietary changes. You could try making them now and start to decrease the amount of carbs in your diet. Instead of the candy bar, you could try a snack high in protein which will not cause your blood sugar to spike and then drop. Some snacks that are high in protein are hummus, peanut butter, you can dip veggies or fruit. There are also protein bars which are quick and easy like a candy bar. However, be careful with these, many are so loaded with sugar they are candy bars in disguise.
I hope this helps.
Cathy
The only wat to know is to test your BG when you feel that way after eating sugar. (or see a MD for proper testing)