Have you tried a Neti pot? Google on where you can buy, if you cant find it at your local natural food store.
I was stationed in Southern GA for the past 3 years and my allergies had become so bad that I was dealing w/ facial swelling (upper lip, both eyes, as well as forehead). It started w/ a deep and intence itch-the kind that you cant seem to get to-and then swelling. I was looking like some one beat me up, minus the bruses and pain. It was just very itchy. Not to menion the "head-in-the-clouRAB" feeling, itchy, watery eyes, sneezing, etc.
In 2007 I recieved a sinus reconstruction and a rhinoplasty; did seem to do much, except take the "hump" of the bridge of my nose. I, pwersonally, would not advise trying this method, as my swelling only seemed to really take off AFTER I got my work done-thus causeing me to breathe better.
I now live in a drier climate it hs seemed to help. The Neti pot is used to cleanse the sinus passages by using saline salt. The first week or so, your throat will brun/itch a little but you will get used to it if you contune use. Also DO NOT swallow the salt h2o, as you could have an upset tummy.
Hope you find some relief very soon, as allergies are a real pian in the rear-end!
Good luck~