I am a beginner and hence did a child's mistake and now i cant enter my system and when I try to enter recovery shell it says "Kernel panic - not syncing attempted to kill init?" and i didn't find any answer on how to solve my error online . I am desperate ...
You can save your personal files (to another drive), if you have enough drive space, save the whole file tree /home preserving the ownership and permissions.
Simple example, boot from another system, for example a live system in a USB drive, mount the partition of your broken installed system to a mountpoint and backup to a tarball,
cd /mountpoint
sudo tar -cvf /path/home-backup.tar home
Maybe make a compressed tarball (slower, but needs less drive space),
cd /mountpoint
sudo tar -cvJf /path/home-backup.tar.xz home
Then you can re-install and later on restore your settings and personal files from the [compressed] tarball.
You can restore by
Change directory to /
cd /
Run the following command to extract everything from the tarball,
sudo tar -xvf /path/home-backup.tar
or
sudo tar -xvf /path/home-backup.tar.xz
