ITunes :: Keeps Freezing On Startup?

A few days ago, my itunes began freezing shortly after startup. It would take forever to get through the "checking library" phase and then once it fully opened it would freeze. This may coincide with it beginning to download some itunes-u content in qeue, but i can't keep it running long enough to get into the store to cancel the downloads, if that's what it is. updating the software but everytime i try it says "software is up to date", even though it was just told me that one is available. I've tried removing and reinstalling and have got nowhere. I may have actually made it angrier. I have over 109 days of music that I can't listen to and and an iphone I can't add/remove files from.