I have been suffering with sinus like head pressure for years. No diagnosis yet, but my prolactin levels have been found to be elevated for the past year. I’m going for an MRI soon to check for a pituitary tumor. My prolactin levels are not that high, so I’ve been told by my endocrinologist that if it was a prolactinoma it would be tiny and not cause my head pain. Not sure I agree though, because this issue started at the same time all my other hormonal issues started. Like you, it feels like a sinus infection, it causes brain fog and cognitive difficulties, vertigo, lightheadedness and feels similar to anxiety panic attacks in the sense that it creates derealization for me, but it is way worse and very painful and real. I’ve tried allergy meds, massage therapy, meditation, nasal sprays, etc. nothing gets rid of it. Feels like my eyes are always heavy and something it’s pulling on them. :/
I have no further input other than I’m in the same boat and I hope you can find a cause soon!