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!
I am sorry I don't have an answer for you, but please keep checking, someone will come to help you out.