Just relax, and carefully search TMO - You will find answer how to reflash Your device (if that is really what it's need). Don't worry and find enough time to read few threads about that kind of cases.

First things first, start from the most obvious things (like bingomion says), battery, etc.

It will be all right, just don't try everything without knowing what You're dooing. Write some more info about Your case, what You did with it before she decided to sleep little longer There is louds of great people here willing to help and having right skillzz for dooing so.