How to fix MySQL not starting in XAMPP

Fixing the MySQL server not starting in XAMPP is done by reverting back the data files pre-issue.

Navigate to your XAMPP MySQL directory (C:\xampp\mysql).
Create a new folder called FIX_BACKUP.
Copy C:\xampp\mysql\backup and C:\xampp\mysql\data into C:\xampp\mysql\FIX_BACKUP.
Paste the contents of C:\xampp\mysql\backup into C:\xampp\mysql\data overwriting all the files.
Finally copy the ibdata1 file from C:\xampp\mysql\FIX_BACKUP\data into C:\xampp\mysql\data overwriting the file.

Your MySQL server should now start in the XAMPP control panel.

Reference :
https://write.corbpie.com/how-to-fix-mysql-not-starting-in-xampp/