Migraines & Clusters are diagnosed when every other possible cause has been ruled out.... unless you have a family history of Migraine. Having 1 parent with them puts you at 50%, 2 parents is in the 90% range of getting them. Do you have a Neurologist? If not you might want to get one because there are medications which may be able to help you, but they can be dangerous (Dr's will pretend they aren't... I CAN'T stand their cavalier attitude over it) so you want to make sure the person helping you knows what they are doing.
My migraines tend to concentrate in a small area too, but generally flow out spreading the pain until I am all over miserable. My DH and MIL get Clusters which are very similar to your complaints. They get theirs in a very specific spot, for them this is a baseball size circle at the base of their skulls and doesn't seem to spread. Their clusters also do not seem to go on for days and days like my migraines do.
The sensitivity for days after an attack is not unusual for these headaches. In my case I can 'feel' a headache hovering between creeping in and creeping back for days after an attack. During this time it is ridiculously easy to re-trigger an attack. All I need to do is smell the wrong scent and wham, there it is in seconds.
I suppose it could be sinus but the fact it resolves itself without needing antibiotics seems odd. I would think an infection bad enough to cause that kind of pain would require a great deal of medicine ect to clear up. Also, sinus doesn't really explain why it doesn't spread unless you have a bunch of closed openings which keep the infection in one place. you can see the openings here:
http://images.google.com/imgres?img...official&tbs=isch:1&ei=PJ5-S86kEZGb8Aba9fy6DQ
If you think sinus then ENT is the way to go.
Back when I was young and getting diagnosed I kept flip flopping between ENT & Neurologist opinions. The reason is I had migraine AND sinus trouble, double whammy. The sinus headaches could trigger migraine, but migraine couldn't trigger sinus. They found the sinus trouble with a CT scan of the sinus' when they discovered deviated septum and 3 sinus openings were blocked. SO a little Pseudoephedrine (Sudafed that now sits behind the counter with the Pharmasist) would work on that part. Unfortunately, allergy season brings on a deluge of migraine for me. The migraines were and are much more difficult to manage, but aren't impossible. Medication has given me a life that I otherwise would not have.
Feel better, good luck and be prepared for people who will act like you are an addict looking for drugs. When you come across these sorts ignore everything that comes out of their fool mouths and find someone else. You'll see them everywhere, Dr's, Nurses, Emergency Room people, just don't let them make you feel like you are doing something wrong... they have a way of doing that.
