Have you had this checked by a doctor?
So many things can cause neck and head pain, and you really should get it checked out. It could be nothing serious (muscle aches) to something very serious. There's no way we can diagnose it here.
If cost or lack of insurance is a concern, and you are in the US, call your local health department and ask if they have clinics for people who have no insurance or are under-insured. You really need to get this checked.
Let us know what happens.