Help HELP: lost contacts stored on phone, apps won't start

[koch11]

I seemed to have lost the contacts stored on my phone and my downloaded apps will no longer start (I get a 'stopped unexpectedly' error when I try to start them).

I still have the contacts pulled from Gmail and Facebook. All the apps that originally came with the phone work, but have been reset (have to redo my settings).

Anyone know what might have happened? How to fix it?