I as well really understand your pain. BE CAREFUL injecting things into your head. There is the simple risk of infection, hitting another nerve, etc. Have you exhausted all other options including narcotic pain relievers? Seems to me like sticking yourself in the head when in severe pain may not be the greatest idea. I'm not trying to say don't do it, just be extremely careful. Everyone always thinks it can't get worse, but trust me no matter where you are, it can always get worse. Have you tried strong pain killers because if you haven't I would definitely pursue something oral, or a nasal spray or even an injection of pain meds from a nurse than sticking a needle in my own head. I find narcotics can take away a lot of the pain, sometimes all and sometimes only a little but definitely better than nothing and better than creating unnecessary risk. Let me know how that works out for you.