Modified my config.yaml file and now I'm locked out

Running a Home Assistant Green. I modified the config.yaml to mute a couple of devices about an hour ago and then I updated to the latest core OS. After rebooting, one of those things caused the screen to hang at "Loading data". All my automations are working correctly. I can access the observer. I swear I enabled SSH but apparently not because I can't log in from Terminal (using a Mac). What's my next step? Thanks for any suggestions.

(I keep backups, and was just about to go in and make sure the backups were saving remotely via Home Assistant Cloud, but this happened first, of course)