I fell on cobblestone this morning. half of my head has a burning sensation( that comes and goes). i hit my forehead above my right eye-brow.

Got to ER or Urgent: Care and get an x-ray done asap. Head trauma can lead to all sorts of problems that can cause issues later on that you may not be aware of. You could easily have a fracture or other trauma and should be seen by a doctor for evaluation. Often symptoms may not appear for another 24-72 hours that are important to evaluate at the onset. So don't delay. Also, have your neck and back evaluated too.