From what you say your simptoms are...look into Occipital Neuralgia to see if that sound like you. I have had this now for over a year and a half. With the headaches only being one sided and the pressure behind the same side eye it does sound like this is your problem as well. Only I do not get the ear pain.
Does your pain originate from the back side of your head on the right side at the base of your scull between your ear and spine? Can you follow it up to the front of your head like following a piece of thread all the way to the top of your right eyebrow...and feel pressure all the way to the back of your eyesocket like someone is pushing it from the inside. I hope not! But, if you can it defenatly sounds like what I have and the doctors tell me that it is Occipital Neuralgia.
Let me know,