I hit my head on the wall laying down in bed very hard was painful i felt mildly dizzy and slight nausea which passed i have headache where i hit it ?

Trauma / concussion: It sounds like you have a post-concussive / post-traumatic headache. If the headache is accompanied by other symptoms (difficulty concentrating, irritability) then you might have post-concussion syndrome. If the headache doesn't clear or gets worse, see your physician. http://www.brainline.org/content/2008/12/headaches-after-head-injuries-8212-post-traumatic-headaches.htm