iTunes nor Appstore works (it's been at least two months)

Hey,

I'm on a MacBook Pro 10.7.5, my iTunes is version 11.02 and my AppStore is 1.1.2 and NONE OF THEM HAVE BEEN WORKING FOR MONTHS!!!!

I wanted to download the new software Lion thingy (the one that allows iMessage) and I can't because I can't access my AppStore. It just WON'T load at all.

At least, on my iTunes it says "an unknown error occured -9806" ...

So what can I do? Please help meeee :-/