Went back to the physiatrist yesterday for a follow-up. Taking Claritin had no effect whatsoever on the headache. I opted to try the trigger-point injections of saline/novocaine. Three shots on each side of my head (high on temple area, kind of behind ear area and in the neck at the base of the skull) were administered. They didn't hurt very badly, more like a quick sting.
I decided to wait until today to send this out so I could report any results, if any. Unfortunately, the headache is definitely no better. In fact, it is worse today than it was yesterday. Since the pain frequently increases/decreases, there is no way to know if the increased pain is related to the injections or not. I have no idea how long it is supposed to take for the injections to work, so I dn't know if these are a failure or not.
That's all I know right now.