Hello, I understand your feeling. I hope you're not in too much of pain. It is very bad that you have been suffering with headache since 3 years. But if the ct is normal Anne even the there is pain and I is continuous then it might be because it is migraine or may be of sinusitis. You need to follow up with the same doctor who is treating you for the same. If not you need to consult a general physician of your locality. Thank you