I agree with Forum-volunteer-cmb that your symptoms sound very much like what we experience when our glucose levels get too low. Borrowing your mother's meter and doing a glucose test when you feel this way would be a smart way to find out. If you ARE hypoglycemic, there are some dietary changes that may help alleviate the symptoms. You may want do do a Google search on hypoglycemia... there are lots of articles on the web about it.
I would recommend going to the doctor and getting checked out. You should probably ask for some blood work-like a fasting glucose test. And think about other things-are you eating well-are you skipping meals-even a healthy person can feel weak if not eating enough and properly. When I am hungry I feel weak and get headaches too. I am diabetic Type I and even if all my blood sugars are fine-if I am hungry and need food or a snack my body reacts. Other symptoms of diabetes are frequent urination, excessive thirst, feeling lethargic all because your blood sugar is rising too high. Your symptoms sound as if you are maybe getting low blood sugars. Does your mother have a glucose meter? Maybe try testing your blood on it-just to give you piece of mind.