Streekgeek, From the first few threads I had a feeling it was a sinus infection. One true and tried test is to bend over as if to tie your shoes, and if you had a heavy throb in the sinus fore head area its probablly sinus.
As for the suggestion to use the nasal rinse called Neti pot, it warns the user DO NOT USE IF YOUR NASAL PASSAGE IS COMPLETELY BLOCKED. So just be aware.
Also, a really good idea but super gross, (gets exciting actually) is to take Fenugreek seed. Either by tea, (tastes weird) or by tablet. Take quite a bit daily. You will be able to fill a mason jar up with thick mucus snot. WHat will come out from your sinus cavity will amaze you. Its soooo amazingly gross.
Enjoy.