I have been feeling excessively groggy after 3pm & sometimes need to lay down in a fog for about 2 hours until I feel better. I an female,43, non smoker, takes birth control, exercises 1-3 times a week for 45 minutes at a times. Intake thyroid medicine also. What possible problems could I be having? Is this a symptom of diabetes or a stroke or a blood clot? I usually have low blood pressure, about a month ago it was extremely high. But then went own to normal. I am 157 5 2