I have the same trouble. Left eye was a breeze, but right eye not so. At one point there was sharp pain. I too have a high pain tolerance. It went away, but I had severe headaches along the right side of my head for several days. Advil did manage it. I talked to my doctor and she said something about maybe a nerve got irritated (I didn't really understand what she said) because the headaches subsided nobody seemed concerned. But they are back intermittently. Not as bad and because I have bad allergies that affect my sinuses, I figured maybe that was the cause. But the pressure and right side headaches are different than my allergy headaches. I never have had that kind of headache before the LPI.
Does it eventually go away? I too am worried.