I Have Been Experiencing An Upper Respiratory Infection, But Went

I have been experiencing an upper respiratory infection, but went out to lunch with my husband today. At the restaurant I had difficulty keeping my eyes open, and when I stood up i was dizzy. I had no difficulty communicating, and did not feel any pain except for a slight headache. On the ride home, I kept nodding off, and when I did open my eyes, I experienced some double vision.