Hi there. I hope your head is feeling better. It seems your doctor is being pretty hasty by telling you it sounds like an aneurysm. Did he order a CT scan or MRI? I have been having pain in the back of my head (primarily left side) and it travels to my temple then to my eye then to the top of my head. I was diganosed in the ER with A-typical migraines and by a pain management doctor with chronic migraines. I have increased headache from physical activity or computer work (as my head is starting to hurt as I type right now).
What kind of a doctor are you seeing? Request a cranial CT and take it from there. You should probably make an appointment with an internist, neurologist or pain management physician.
Also headaches at the base of the skull can be caused from strained muscles, particularly in the neck. During my evaluation yesterday the doctor told me that my neck muscles on the left side were very tight and hard and that my neck felt rigid.