i have been experiencing nausea, severe headaches, i get this hot numbing pain in both sides of the back of my head it starts as a hot numbing then get cold and feels like as if your hand fell asleep and you re poking at it, i feel that on my head. i wake up multiple times at night. i have lost my appetite, forgetful memory, and sometime i get a sharp shooting pain close to my spine. weakness in right arm, what could it be?