I am confused by what the issue is [Nvidia driver]

It is important to know exactly what the error message says in a case like this, because it could be a number of rather different things happening.

There have been a lot of issues reported for this driver. It is possible your problem is GPU-related. Next time you get a hang like that, see if you can switch to a TTY and troubleshoot from there. Computer doesn’t boot, boots to a black screen, or stops at a message

Some users are reporting a number of resolved issues with the 555 drivers. They are still in beta at the moment, so be warned: here be dragons and so on. If you’d like to give them a shot you can install them like this: New nvidia drivers (beta 555), suggestions on how to install? - #4 by BluishHumility