sudo: /etc/sudo.conf is group writable

I've made a mistake. List of commands that I typed:

sudo usermod -a -G root erpsudo chmod g+w /etcsetfacl -R -m u:erp:rwx /etc

Then ssh.service of the virtual machine stopped working and when I type commands with sudo in terminal, it says:

sudo: /etc/sudo.conf is group writable

And after googling for some time, it seems what I have done is similar to chmod -R 777 /. I'm hoping that I don't need to reinstall the Ubuntu OS on this machine.

Is what I have done actually revertible?