Problem updating Sequoia

I'm running Sequoia on my iMac, and I'm trying to install an update. When it gets past the load screen, it just goes black. Not like the screen shuts off or goes to sleep; more like it's greyed out. The cursor is still visible, and I can move it around the screen, but there's nothing on the screen. When I tried again, I got an error message:

I was thinking about erasing the disk and restoring from Time Machine, but I don't know which disk to wipe.

Any advice?