After I ate breakfast yesterday, almost immediately I started shivering uncontrollably. Thinking I was just cold, I put on a light jacket and went to work. However, the uncontrollable shaking interferred. This uncontrollable shaking lasted for about three hours. Just guessing here, but I eventually threw up and notice it was mostly my breakfast, a sausage and egg biscuit. After throwing up, the shakes seemed to subside and then I became very, very tired. I could not keep my eyes open. I went home at noon and all I did was sleep. Very, very tired. Went to bed early, 7:30 and slept most all night. Today, I have a really bad headache. Not nauseated. Ate a small bowl of cheerios this morning. Any ideas?