Is it possible it's from an allergy or a latent sinus issue? Because it sounds something is causing the membranes inside of the nose to swell.
It can be a food allergy, a contact allergy: my mom gets a completely plugged nose if she drinks a glass of red wine, as an example.
Steaming your head over a bowl of hot water with some Vick's Vapor Rub in the water may afford you some relief, as may a camphor 'stick' inhaler than Vick's also makes.
If it's been going on for more than 10 days, however, I'd suggest a trip to see the family doctor.