That is the latest kernel on 18.04 which was just released via the HWE.
That means there is an issue with the nvidia driver and the kernel. Sadly this kind of issue with nvidia drivers is not not rare.
The Esc is for accessing grub when using EFI boot. Shift is used with Legacy/BIOS boot. Based on the hardware you are using I anticipatedyou were using EFI. Try using one of them during the boot process and if that does not work try using the other after you restart.
We just saw another user who seemed to be having some issues with the newest 18.04 kernel. I'd urge you to file a bug on the kernel when you get back into the system.
Apt history is stored in var/log/apt/history.log you can view that by running pluma /var/log/apt/history.log
Before we dive down the rabbit hole that is nvidia drivers lets see if rolling back works and see if there is anything developed on bug reports for this.