Head pain severe horrid, what to do?

See the doctor. New onset headache, abrupt onset of a new or different type of severe headache and/or "worst" headache the patient ever had; are few of the red flags of the secondary headache. The patient could have more than one primary headache disorder and even a patient with a previously diagnosed primary headache could have a superimposed secondary headache. Rec to see headache specialist asap.