Severe congestion...PLEASE HELP!?

I went to the walk-in clinic saturday and was diagnosed with a sinus infection and was put on antibiotics that day...3 days later (today), I am still COMPLETELY clogged up. I can't get air in or out of my nose and I am unbearably uncomfortable. I am taking sudafed, mucinex and have tried saline spray. I'm desperate here. PLease help.