Running into this issue "MySQL shutdown unexpectedly". The most probable cause of this issue is related to port. MySQL uses 3306 by default. If another computer application is using this port, MySQL won’t start, leading to the shutdown.
So, to Ractify this issue, We need to first check for if other application is using the port 3306.
Step1. Open cmd as administrator type this command "netstat -ano | findstr :3306" this will list all processes of the port 3306 with their process ID's See below screenshot.

Step2. The next step would be to kill the task this port is using by it's process ID got in the previous step. for this we will again use a command "taskkill /PID 6092 /F"
This will kill the current process and you can start mysql from xampp again.
You can also end this task from your task manager in windows as well.