Missing icons

My phone went crazy this afternoon and the screen went blank. I decided to turn it off and back on, but when it came back on, my messages icon is gone and I can't access my messages. I previously had my front convenience key set to messages also and not only is it not set to messages now, but messages is not even an option for setting the convenience key. Help!

What if you try another battery pull?

I've pulled the battery 2 or 3 times at this point and it isn't helping. I appreciate the response though. : )