Alrighty, so I have had to deal with a similar problem all throughout using Ubuntu with Nvidia. But with the new 17.10 update I have been getting a new recently discussed bug which results with my screen going into a black screen and looping "stopped user manager for uid (#)", this prevents me from going into recovery mode and accessing grub directly from the computer as holding the keys on startup doesn't do anything.
So as a workaround I SSH'd into the desktop and have tried some workarounds that I've heard around random forums.
- uncommented "WaylandEnable=false" in (/etc/gdm3/custom.conf)
- "nomodeset" in grub (/etc/default/grub)
- reinstalling the drivers after and before
These attempts changed nothing in the outcome of the issue. The only thing that has helped was removing the Nvidia drivers which I've initially installed through the Software Update GUI, which rendered the device bootable.
Hopefully y'all can help me utilize good ol Nvidia drivers again ;-;