You may have a Cluster Headache. This typically hits fast and hard, and disappears without a trace.
ClusterHeadaches.com - this is the best site in the world for this information. You can get immitrex for this but you have to use the hitter needle - pills aren't fast enough. Read about clusters and see a doctor.
If that's what you have you owe me a badass dinner or an assload of traffic or you buy my content.