M.J.
Hold your nose, close your mouth and blow pressure out your nose. Be careful you could blow your eardrums if you do it too hard.
What will help is getting a good decongestant. Sudafed (not the PE). In our state you have to ask the pharmacist for it, but you don't need a prescription - just your I.D.
Also take an anti-inflammatory like Advil or Motrin. Not Tylenol. Take about 3 of them every 4-6 hours.
Sleep with a humidifier and prop your head up to help your eustachian tubes drain.
I have bad allergies and a deviated septum. I battle congestions and clogged stuff all the time. This is what works best for me.