Broken system and boot after system update (possibly nvidia-340xx-dkms)

I do remember a few programs-packages being updated: linux, chromium, firefox-developer-edition, etc, i do not remember much more, i am on a Live CD right now i’d need to chroot to find out and i am not really very good with that, not sure if i can be very helpful
I’ll try to watch the video and see what i can do
Btw i had managed to get the drivers installed for the nvidia a few days ago thanks to the help of the forum here, you can check the topic for more information: