I have a recent Apple silicon Macbook Pro running Monterey.
After a reboot, my user name vanished from the login screen. I am the only user, so there is apparently no way to login.
By holding the power button, I can boot into startup options. From there, it asks me to "select a user you know the password for", and here, my login name/photo appear, and I am able to login to macOS Recovery mode.
In recovery mode, I can open up a terminal window. From there, it appears that much of my data is gone: for instance, my home folder is not in either
/Volumes/<my_disk_name/Users. I don't know whether this is because the data is truly gone, or because it is concealing it from me due to encryption or something.
I'm wondering if anyone has any suggestions for how I might try to recover my user account. I have found some previous posts but they all seem to be for Intel macs and older versions of the OS. I have a Time Machine backup from an hour or two before the computer died but I'd rather avoid losing my last hour of work if possible.