Hi,
I have several suggestions.
First, add a sinus rinse to your routine. They sound gros, but they are so effective.
Another thought is to cosider trying Patanase instead of the Astelin. Astelin wasn't a problem for me, but it sucesseors Astepro and Astepro 0.15% were horrible. I felt better when I didn't use the med then when I did. I got very congested after using it and it lasted about 5 hour with constant, Astepro drainage.
Lastly, it may be time to consider allergy shots.