Before you head to the Genius Bar, the only thing that I can suggest at this point is to try a Forced Restart on the iPhone.
Force restart iPhone - Apple Support
This is a bit tricky for some users.
Quickly press and release the UP button
Quickly press and release the DOWN button
Hold in the SIDE button and continue to hold it in for another 20-25 seconds while ignoring the "slider". You have to keep holding until the Apple logo appears in the center of the screen. Then....you can release the SIDE button.
If the Forced Restart does not help, you are likely looking at erasing the phone and reinstalling the iOS software. Make an appointment at the Apple Store or take the phone to an authorized Apple service shop in your area for "in person" help.
Good luck