What Causes Splitting Headache In One Side Of My Head?

ive been having a splitting headache now on my right side of my head above my eye now for a month or so i sometimes get really really sharp pains in my chest which spreads down my left arm and goes numb. Felling sick to stomach also and I am also experiencing dizziness all the time now. I have had this before and no one could figure out what was wrong i didnt know if maybe someone could help me out?