Hello Casandra,
When you become badly dehydrated your blood pressure can sky rocket sometimes. It's possible for it to go up to 200 or better. You may also have mineral deficiencies in potassium and magnesium. Shaking is common as well under your conditions. It is possible that you may be diabetic because diabetics often become dehydrated even when they drink a lot of fluids. This often happens with hyerglycemia. Excess sugar in your blood stream can made you very thirsty so you drink a lot of water which in turm makes you pee a lot. Your kidneys are trying to work over time to get rid of excess sugar in your blood. I think its a good idea to go to the doctor as soon as possible and get a physical done so that you know what is going on. There had to be a reason for your symptoms and they sound serious enough to warrant checking out.