I know this post was from a while ago, but I was wondering if anyone had any ideas, or if the original poster could tell me what happened, as I've got the exact same problem. Mine's lasted a week so far.
I don't have the headaches when I wake up or later in the evening, but in the middle of the day they can be extremely severe. I've had an eye test, the optician didn't find anything, and I went to my doctor who didn't seem to know what it was.
Please help, I'm starting to worry a little.