I would check for biggest files and remove them manually.
There are tools that assist in dissecting the biggest files in your partition/disk/system.
KDE based: Filelight
Gnome based: baobab
NCurses based (text terminal - no gui): ncdu
A quick alternative to the above is using core utilities which are most likely pre installed in any modern linux distro:
sudo du -a {{BASE_DIR}} 2>/dev/null | sort -n -r | head -n 20
Where: {{BASE_DIR}}
is the root directory of the lookup, and 20
is the number of top sized files that you wanna see.
Do you have any virtual machines installed? You can use something like this to see where it’s all contained if you can free up enough space to install it. https://wiki.gnome.org/Apps/DiskUsageAnalyzer
PopOS comes with Apps/DiskUsageAnalyzer - GNOME Wiki!, which imho has a better overview of what is really being used.
As far as I can see Gnome Usage considers everything not under /home to be part of your OS. Which includes the rescue partition etc. I find it not a very useful app, and prefer Disk Usage Analyzer.