iPhone logo keeps reappearing as if restarting

I need serious help here...

So, I just FINALLY decided to update my iPhone 4 to iOS 7, and it told me that it needed to restart to install... I allowed it to, but now, it seems as if my iPhone keeps restarting. The Apple logo keeps appearing on the screen, then disappearing, then reappearing again... I NEED HELP HERE!!! Even when I plug my iPhone into my computer, neither my computer nor iTunes can detect it( the place where the icon for my iPhone usually is stays blank as if there was no device plugged in), so I can't continue the update or use the restore option...

Any help would be appreciated.