Sinusitis-puffy eyes but no nasal congestion! Help!

about 3 months ago, I started to feel a really weird sensation coming from behind my eyes.  I have never had a sinus infection before and I thought I was going blind!  I could see, technically, but the weird pressure feeling distracted me to a great extent.  I have been treated with 4 different courses of antibiotics (Zithromax twice, Biaxin, and Levaquin) and steroid nasal spray, but nothing has worked.  Still waiting for my CAT scan.  The doctor recommended taking antihistamines while I was waiting for the CAT scan, and I am taking Aerius 5mg. 
 
So far, it doesn't seem to be working.  My only symptoms are overall tiredness and really puffy eyelids and post-nasal drip.  A feeling of pressure behind my eyes.  I have no nasal congestion! It is very confusing and any advice anyone has would be greatly appreciated.  Any home remedies, any tips, or just those who have the same symptoms. 
 
I am also looking for advice on the best antihistamine to take for my symptoms.  The Aerius doesn't seem to be working.