I have the same problem. What works for me is to combine several different meds. Get some ceterizine HCL (generic Zyrtec) and loratidine (generic Claritin) and some type of allergy nasal spray (I use Omnaris, which is prescription). If your eyes are also bothering you grab some eye drops for allergies too. I know it sounds like a lot but if you use all of them every day you should feel better. I have allergies in the spring so bad that I have to take all of the above in order to function...otherwise I'm so dizzy I can hardly get out of bed.

You could also look into getting a saline nasal wash bottle...you can pick them up at Walgreens or another comparable store. I've never used mine for allergies but it works really well to get sinus infections cleared up so it might do you some good to get your sinuses rinsed out.

Hope this helps!