Taking anti-migraine medication is only useful if you have multiple episodes in a month. The is medication to prevent migraines from occurring (or better decrease the frequency) and there is medication to treat an attack. A severe headache is not the same as a migraine however. Migraines are usually ‘announced’ with a prodrome (scattering light in the corner of your eye that becomes bigger and bigger or a weird taste) and the headache is often accompanied by nausea, vomiting and photophobia. When reading your posts, I suspect that you ‘just’ have a headache (can be just as bad!). Take 2 acetaminophen,hydrate (0,5l water) and a nap and you are often ok again! When you actually experience the previously stated symptoms; go see your general practitioner. They can do a full history and exam and decide in accordance with you which medication is best suited!