Treat my seasonal allergies and.. cats?

I have extremely bad seasonal allergies. They were.. I suppose you could say manageable up until this year. I live in the Minnesota and it's supposedly the "worst year for allergies" and I totally agree! I've had itchy eyes like crazy, sneeze attacks the second I open the door or window, sore throats, just sorta drowsy. I am also sort of allergic to cats. Not too bad, only if I spend a very long time with them. Here's the thing: I volunteer at my local humane society for 3 hours twice a week. So I need some ideas for how to get rid of some symptoms (temporarily of course). I take an over the counter form of allergy medicine. The only thing is that it barely helps. Thank you!