It sounds like an incident of reverse squeeze of the ethmoid sinus.
It could have been related the use of an oxymetazoline nasal spray (e.g., Afrin) if the med began to lose effectiveness during the dive.
Make sure that you are timing doses appropriately and not overusing the spray.
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such.