Kali - Black screen while shutting down x server

Hello all,
I have installed Kali in my hdd (which has Windows 8.1 too), when i was trying to install the nvidia drivers i had a problem:

This problem came when i executed those commands:

Quote:

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sed 's/quiet/quiet nouveau.modeset=0/g' -i /etc/default/grub
update-grub
reboot

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So now when i try to shut down the x server, with the following: CTRL + ALT + F1 or service gdm3 stop, i have a black screen with a flashing slash (on top left).

I hope you can help me, thanks!