I've been suffering from chronic daily headaches for 18 years (I can remember the exact day they started).
Although I don't have migraines (no auras, nausea, sensitivity to light, etc), the drugs which my neurologist tries with me are the same as you'll see discussed on this forum as migraine meds. As I understand it, most headache docs and researchers think most headaches are related and thus respond to similar therapies.
This actually sounds like a case of "new daily persistent headache," which is what I also suffer from. The qualifications for it are outlined as:
A. Headache for >3 mo fulfilling criteria B-D
B. Headache is daily and unremitting from onset or from <3 d from onset
C. At least two of the following pain characteristics:
2. pressing/tightening (non-pulsating) quality
3. mild or moderate intensity
4. not aggravated by routine physical activity
D. Both of the following:
1. not >1 of photophobia, phonophobia or mild nausea
2. neither moderate or severe nausea nor vomiting
E. Not attributed to another disorder
It's known for it's sufferers to commonly remember the exact day in which they started (after which or soon after which they become unremitting). Unfortunately, as you may have noticed, it's also known as one of the most resistent to treatment of all of the headache classes.
A good summary site is: http://headaches.about.com/od/otherheadpain/a/ndph.htm