I wonder if this "headache" was rather in fact because of the air expansion in your sinuses which can occur upon descent.
This is common in people that have congestion, or a cold, or issues with their sinuses. In your case, the frontal sinus is an area above the eye, in the forehead, and if there was difficulty in the sinuses being open (from some sort of recent cold, congestion, allergies, etc) - you can have sudden pain in the face during airplane descent.
The fact that this headache was sudden, and so specific in it's location makes me think that this is probably likely.
Sudden, severe -- all over headaches could be an issue with a bleed in the head, but then you would continue to have a severe headache, and it would be everywhere, not just in a specific location.
Just a quick question - I have to fly home tomorrow and will visit my doc about a possible sinus issue, to confirm your suspicion. Should I take a decongestant before I get on that plane to (try to) reduce the chance of this happening again? Or will that not help?