from the description you have given ayurveda guides that you have vatic imbalance in your body. Dryness and shooting nature of pain associated with thirst are symptoms of excess of vat. The sudden weight gain calls for thyroid
investigations. You have not mentioned about your hypertension
and state of digestion. Are you constipated also ? Detailed prescription of herbal medicines can be made after hearing from you, for time being you can start with Garlic clove which will help to restore imbalance in vat.