I have been sick off and on for a week. First I felt like the wind was knocked out of me. Then my stomach would hurt really badly for about 15 minutes. Then I developed a fever and pretty much hurt all over. Today I felt much better, and I took a nap and woke up feeling horrible again. Later in the day, I notice that I was starting to sweat, and before I knew it, my pillow, sheets and clothing were drenched. After that I felt much better and my fever was gone. If my thermometer is correct, my temperature is 95.1. Does this happen often and what does it mean?