Code:
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 182G 161G 12G 94% /
/home/glibguide/.Private 182G 161G 12G 94% /home/glibguide
I assume you are bind mounting /home/glibguide/.Private to /home/glibguide? If you do not mind explaining the reasoning that might help.
That could be why used space is being reported as 321.29 GiB. Its possible this is the reason the file browser is slow as well as some applications. I am not sure about the other symptoms.