My daughter had a constant headache for two weeks a few years ago. She also didn't have the classic migraine symptoms, like an aura or anything, but finally saw a neurologist, who prescribed the migrain medicine Imitrex taken orally. It knocked out the headache. And has worked well ever since. But they had done an MRI (why are you getting a CT scan?) before the medicine was tried and she has a small "abnormality" that they recheck her for every so often with a repeat MRI. It hasn't changed in three years and we are told it may never change. But the headaches are less frequent and still the Imitrex works great. I think you should get one of your doctors to presribe a few doses to see if it works if you have had a headache that long. I wish my daughter could have tried it sooner, even though she didn't have the "classic migraine" symptoms. Good luck.