ITunes shuts down when connected to iPad

I have a jailbroken iPad 3 on 6.1. I've been trying to update it to iOS 7; however when I take the steps to update it iTunes crashes. The iPad will remain in recovery mode and iTunes refuses to open while connected. When I take the iPad out of recovery mode it will connect to iTunes as usual, but the same problem continues. Please help. I've tried everything I could think of. Cydia is not even working now. Your help is greatly appreciated.