I am sorry I don't have an answer for you, but please keep checking, someone will come to help you out.
Hi
Welcome to the MedHelp forum!
If you are still getting pain on and off after 4 months, it is important to get a MRI. Other than brain related cause, this can be due to TMJ (again due to injury), temporal arteritis, dental ache or due to an eye or ear problem.
Since I cannot examine you and know other related conditions you may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP for primary examination followed by proper referral.
Take care!