Can Pressure Headaches, Nausea And Dizziness Be Due To A Previous Accident?

i hit my head on a wall 4 weeks ago, i saw stars at the time and the top of my forhead hurt, but the all seemed fine after that. For the last week i have been ill with pressure headaches in the temple area of my head and nausea, i have been very tired and dizzy yet i have not been able to sleep well just 2 hours at a time. could this be from the accident.