Well, I've been dealing with this. My sinuses are so swollen I can't do the neti pot and it's causing really bad headaches. Something that might work for you is Afron, or the generic brand (about $6 at CVC.) I hate it, but I guess it's addictive. It feels like acid going in my nose, but it really opens everything up, and you will start dripping everything out for about 8 hours. If that doesn't clear it up, I don't know what will. My doctor warned me NO MORE than three days because he finds a lot of people get addicted to it.
2x Mucinex. The generic (guaifenesin) kind aimed at sinuses works freaking wonders. Drink a lot of liquids; it doesn't work right if you aren't hydrated, and keep a stack of tissues handy because you WILL be draining like a downspout.