Concussion/tbi? shocks on car are poor, was traveling ~85mph and hit bump/dip.didn't hit head; dull headache ~1hour later,slower at math than usual.

Not likely: Traumatic Brain Injury is caused by a significant force forcing the brain to move too much in the skull causing it to strike a surface or rub against one of the jagged surfaces. From what you describe, it is unlikely. It is more likely a form of whiplash. Any pain will cause a distraction and slow your thinking. Check this out: http://www.medicinenet.com/head_injury_symptoms-page2/views.htm