Working With a Headache

No, I'm not talking about a person or thing. I was actually working with a terrible headache. It hurts so bad. Not sure what has caused it. All I know is that the day drags by when you have to work with this kind of pain. I had this headache yesterday. I was so drained of all my energy when 5:00 came rolling around. When I finally got home, I laid in the dark and rested. My headache continued till I went to bed. I took some Alive and finally went to sleep. Much to my surprise, my headache was gone when I got up this morning. I got my handy bottle of Alive with me - just in case this sucker returns. What sucks about this headache is that I had it for 3 days. I wonder what has caused this pain. I hope it doesn't return.