Congratulations on you new baby! I hope you get your sinuses straightened around. I don't know where you live, but pollen counts where I live in the northeast are off the charts. My sinuses give me lots of discomfort and pressure from just going outside.
I find nasal washings to help a lot. In case you're interested, here's a link to some information:
I do nasal washings twice a day ALWAYS, and during pollen season or when I have a sinus infection I do them more often.
My asthma/allergy doc told me to use this recipe:
1 pint distilled water (no chlorine, chemicals, etc. to irritate)
1/2 tsp kosher or sea salt (again, no anti caking agents/chemicals)
That way you don't have to buy the prepared stuff.
Just a thought, in case what you're experiencing is an allergic sinus issue.
I hope you get feeling better soon!
Enjoy that little baby!