If you haven't already, you should see a doctor to discuss your symptoms. Your symptoms all fit reflux but that they aren't helped by the meds is worrisome. Have you been taking the Prilosec regularly? It can take a few days to a few weeks to feel the full effect.

Also, another thing to consider is your bowels. You can feel very gassy like this if you are having issues with constipation. Basically the plumbing gets backed up causing all sorts of issues on the upper end.

The nose issue is more common with reflux than people realize. Basically acid in the esophagus causes an irritation which the body responds to with inflammation and mucous production.