doing some research into this myself, i came across what i believe to be the source of the issue… the only libgl (a thing xorg depends on) available in the 18.04 repos is the mesa one, which breaks the nvidia-304 driver… might try something on my own.
edit: reread some of the comments. install 17.10, enable the canonical partners repo add the graphics drivers repo to the sources list, sudo do-release-upgrade