Alarm clock glitch

my alarm went off this morning I was looking at the screen which for about 10-20 seconds had all the correct buttons available to then suddenly the screen glitched and came back up however all the buttons were gone I was able to screen shot it the only way I was able to stop my alarm was to hit the charge port on the heal of my hand a couple of times, this phone has never had water damage any other serious damage please explain why this is happening as it is not the first time. (Photo is post screen glitch)