Sometimes locks up when trying to open desktop after hours absence

Sometimes locks up when trying to open desktop after hours absence. Overnight or left all day when I put in password to reopen desktop, instead of opening immediately as usual, the spinner just keeps spinning. When I try the restart the whole thing locks up, and it is even hard to hard power off, holding down power button, sometimes even unplugging does not immediately stop, and clicking goes on inside.
I eventually restarted in Verison 13.? advanced options and did a clean up, including GRUB, and it is so far working but I have not left it alone for any time.
Any ideas? I'm a little wary of Bleachbit, but will use it if recommended.