In most of the cases very severe headache is predominant symptom of meningitis in adults.
This is often followed with rigid neck, painful neck when the one tries to touch the breastbone with the chin (it may be painful when the head is rotated, too).
You are indeed suspicious for meningitis, and because your symptoms last longer than a week, means they are chronic ones, you may be infected with some virus, tuberculosis, syphilis, fungi, or you may have meningitis due to other process in your body.
Sometimes, drugs, even anti inflammatory ones can trigger meningitis (environmental toxins must be taken in consideration, too).
Visit your physician or even better find doctor of infectious diseases!