I suffer from sinus problems a lot. Of the many products I have tried, the hammer and nails work best.

But seriously, what I recommend is using Vicks nasal spray (if you can still breathe just a little bit through your nose), the 12 hour Vicks spray. It works wonders. Initially, you'll feel searing pain for a few seconds (you're sniffing Vicks whole) and it'll make your eyes water a little, but it'll kick in within 5 minutes, and you'll breathe for about 10 hours (it probably won't go for 12. It goes up to about 5-7 hours for me).