OK Tracy. This does sound like early flu and your temperature may rise fairly soon now.
That said, any severe headache requires an exam by a doctor and an MRI of the brain if warrented to rule out a leaking aneurysm so I'd suggest you see your doctor right away or get to an ER just to play it safe
Let me know if you need any more information please
I think it is the flu Tracy--certainly you have the right symptoms.
No, this isn't cancer, of that I'm certain