Ctrl-Shft-F!2 should give you user access (not root)
If the error is in fstab
% sudo mount -a
should give you an error message, you say through chroot it doesn't.
your system freaking out in such early stage may be read only
% sudo mount -o remount,rw /dev/sdxxx /
edit your /etc/66/init.conf --> verbocity=4
reboot, go to tty12, scan /run/66/log/0/current for {unable fail error}
grep -i unable /run/66/log/0/current
usually the first error message is the culprit.
Also, is your bootloader or kernel name linux linux-lts linux-hardened of the image changed?
Maybe use mkinitcpio to remake the image. Do you also have a headers part of the kernel?
Interesting