Critical!!!!!!!!
Call your doctor - tonight if you can reach him. I've had blood pressure problems for years and know a lot of the danger signs. He'll probably have you go to the ER (or at least an Urgent Care) to have your blood pressure taken. If your blood pressure goes too low, you'll straight-line - in other words, your heart will stop beating. Don't wait; I'm not a doctor, but I'm pretty positive you're in a dangerous situation. Please let me know after you've been checked out.