Xunzi_23
Do you have a back up of your system, boot from that, does it shut down normally.
If you do not have a working backup: before doing anything else ensure your data
from home or other storage is is safe.
You can also boot latest antiX full live and see if that shuts down normally.
Also check if you have enough free space on root and home ?
Lack of enough disk space is the only reason I have seen for such an issue, but
there are plenty of other possibilitys, it is not always easy to dignose.
Maybe also do
sudo smartctl -a /dev/sda | less and post output.
interpretation of the result is like palm reading, no warranty.
If your drive makes any weird noises replace it fast.
Side note: usually slow shutdown issues are a well known “feature” of systemd