I am Vinod. I will try my best to help you resolve this issue.
Sorry to hear about your issue :(
Unfortunately, the only way out is to restore the iphone to factory settings. This will wipe out everything on the iphone, but if you have a backup either in itunes or in icloud, we can get everything back.
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 for 30 sec. The iphone screen should now show a USB cable and an itunes logo and you should get a message in the computer that the iphone needs to be restored.
Restore the iphone now. Let me know if you find any difficulty