XPS 15 9560, constantly fails update

My laptop gave a notification that I had an important update pending, which I did. When I booted my computer again I got:

"Your PC ran into an issue and needs to restart. We're just collecting some error info, and then we'll restart for you. Stop code: 0xc000021a".

My computer restarted a few times and then gave me the "Choose an option screen". I went through each option and even the reset didn't work "We were unable to reset your computer". 

I contacted Dell Support, and they couldn't help me and after some searching on YouTube, I tried a recommendation on a video, which was: Choose command prompt from the "choose an option" screen and enter the following: 

dism /image:C:\ /cleanup-image /revertpendingactions 

I let this run, and it restored my computer to a previous restore point (which was interesting, as the system restore option had failed previously when tried). 

I finally got my computer up and running again and used the Dell Support Assist to update everything, which resulted in putting me back at square one, error 0xc000021a - none of the "choose an option" options working. I repeated the "revertpendingactions" process that I did previously and now here I am. My computer is up and running again (for now), but seems to stop working when I attempt an update. Has anyone else had this issue?

Additional info: Last failed update: 0x800f0845