Sorry to hear about your issue :(
Unfortunately, the only way to get out of it is to restore the iPhone.
Open iTunes in the computer and connect the iPhone to the computer. Now, on the iPhone, press and hold the power button and the home button together until you see an apple logo. The very moment you see the apple, let go off the power button, but keep on holding the home button for another 10-15 sec.
Your computer should now give a message that it has detected an iPhone in recovery mode and needs to be restored.
Restore the iPhone now and finally choose the latest backup. Let me know if you find any difficulty.