Lite no longer starts since last update

[Peejay]

I'm no guru but I would start by checking the disk and filesystem. It might recover your boot, it eliminates a common cause and it won't complicate further problem-solving.

I find the easiest way to start a filesystem check is from the Grub Recovery Menu. At the Grub prompt where you would normally use the Linux Lite option select the next one down 'Advanced' which then gives a Recovery option for each kernel on your system.

Selecting the topmost of those will bring you to a list of recovery actions you can take and you want to select Check filesystem (or similar wording, sorry, don't have it in front of me). Once that's complete you can try the 'resume boot' option and see if you get your desktop back. If not, then at least you've eliminated one basic possible cause.
I found this link helpful in finding my way into & round the Recovery menus
https://askubuntu.com/questions/150367/h...overy-mode

Good luck