One alternative thing you could try in arch-chroot is look at file /var/log/pacman.log to see what are the latest updates, and try to update them again.
But before that I’d recommend backing up to an external drive any personal data you have on the machine.
In addition, for the future, look at the REISUB thread on this forum:
https://forum.endeavouros.com/t/tip-enable-magic-sysrq-key-reisub
It may be really helpful when a machine gets stuck.