Many reasons exist as a possible cause for a headache. According to your description,I can only advise that you visit your GP and request some basic clinical examinations. The eyes and ears should be examined as the diagnostics would be useful for excluding possible eye or ear disorders as a reason for the headache. An MRI or CT-scan of the head is also useful in order to exclude some type of brain disorder as the cause for the headache. In the end, it is a process of elimination and you can approach your condition like a deductive sleuth ... but be sure to use the resources available to you and consult your doctor!