my comp is saying my disc is full and no longer functioning properly

Free up storage space on your Mac

What is “Other” storage on a Mac, and how can I clean it out?

OmniDiskSweeper

See used and available storage space on your Mac

• Other: Contains files that don’t fall into the categories listed here. This category primarily includes files and data used by the system, such as log files, caches, VM files, and other runtime system resources. Also included are temporary files, fonts, app support files, and plug-ins. You can't manage the contents of this category. The contents are managed by macOS, and the category varies in size depending on the current state of your Mac.

Space in your computer is called storage. iCloud storage is a completely different thing. It is not really backup. It "mirrors" what is in your computer and thus will also change. if your computer's storage gets too full the computer will stop functioning. You can clear up storage by deleting any unneeded files you no longer use. If that is not possible, I suggest that you insttall an external disk. Then you can transfer files onto it and delete them from your HD o free up space. External disks are now reasonably priced, easy to connect with a provided USB cable, very compact and most do not even require external power. A quick and easy solution.