Terrible things happened!Config.php Was reset!

I modified the config.php file today, there is no check when saving, there may be errors.
After saving and a few minutes, I found that I could not open nextCloud.
I reopened the config.php file and found that all the information was lost. Only these are left

$CONFIG = array (
  'instanceid' => '**********',

what should I do now? I have uploaded hundreds of GB files and I don’t want to reinstall the system. Is there any way to recover? I built it on my own host and used the xampp system.

My nextCloud version is 17,0,0,9, and OS is CentOS Linux release 7.6.1810 (Core) .