What the heck happened to my iPhone 12?

I have no idea what just happened to my iPhone 12. All of a sudden it just stopped working. My touch screen went completely dead. It would not respond with I touched it, and tapping on the notifications on my screen got no response either. So I tried to reboot it. That didn't work either. It would not reboot. It's like the phone was dead or something. So, I finally banged it really hard on my desk a few times. That worked. It finally started responding.

I've been getting notifications about an auto update, but I only plug my phone into the charger when my battery is low, and it wasn't until today that my battery was low enough to charge. So, what the heck is going on? This has never happened to me before, and I'm completely thrown. Thank goodness I also have a landline. Heaven forbid I had an emergency and had to call 911. I certainly wouldn't have been able to call 911 on my iPhone. And BTW, I really DON'T like to slam my phone down on my desk either.

Thank you in advance for your help.