Have you tried Afrin? You have to be careful with that stuff, and although it says you can use it twice a day, I save it for nighttime use only. Works wonders. You are instantly decongested and can breath again.
Also, if you're really congested have you tried going for an easy ride? I was really sick last week and this week I'm not too bad but coughing every now and then and some dripping through the day and night from the sinuses. I went on my first ride in a week - an easy 16 miles to downtown and back - and wow my sinuses drained like crazy. Snot rockets everywhere. But now I feel great and can breathe again. Might be worth a try...
HTH