“How do you treat hypnic headaches?”

I would see your doctor to make sure it is not some underlying medical issue like high BP, low blood sugar, elevated intracranial pressure (i.e., from a brain tumor, etc.), or medicine (or caffeine) withdrawal, to name a few. There are a number of treatments available once no underlying cause is found.

I would simply like to make sure you have been evaluated by a neurologist. As a primary care doctor, I would hesitate to make this diagnosis without being sure other causes were ruled out. Caffeine is actually a common treatment for this type of headache, also indocun or lithium might be used. But I suggest getting your treatment from the diagnosing physician.