Your symptoms are identical to my symptoms of low-
blood pressure and dehydration. I know now how to recognise the symptoms and the first thing I did after the dizziness, fainting, sweating, and shaking chills, was to check my blood pressure. My BP was 67/58/70. A normal BP is about 120/70/70. I began drinking 8 glasses of fluid a day for a week, and all the symptoms disappeared and I felt fine. Try flavored water to help you drink the daily amount of fluid.