I guess you had a brief allergy drop honeymoon and then a rebound?
Light sensitivity is very common with dry eye. Many are particularly sensitive to fluorescent lights in big stores, airports etc.
Certainly there are connections between sinuses and dry eye. What it is and how it works... I really haven't a clue.
I think that - after talking to your doctor about why the allergy drops are no longer working - you should go back and read the many comments in the threads Gretchen provided the links to. Lots of good leads to explore. No one is trying to diagnose or fix you: We're here to share thoughts and ideas with each other. Showing a little appreciation for others' efforts is always welcome
The Dry Eye Zone