You could also have GERD. I often awaken stuffed up after lying down in bed. I did allergy shots for years and blamed it on allergies, however my last allergy test was negative. This year I had an EGD. Come to find out, I have a patulous gastroesophageal junction, which now they believe can be linked to chronic sinusitis. Eustachian tube dysfunction can also contribute to nasal congestion as well. Best of luck.