What Causes Nausea And Dizziness After Head Injury?

Hello. I hit my forehead on the floor twice last night (not very hard), and today I have feeling nauseous, dizzy, a little faint, find it difficult to read and have tingling on the top of my head. However- no vomiting or blacking out. I had a major hit to the head four months ago and was sick for three months so I'm concerned that maybe my brain wasn't healed completely and so I may have been injured from the light hits yesterday? I have a follow up neurologist appt in nine days already. Should I wait or rush myself to the ER to get another MRI?