Large memory space taken by iCloud Drive

I only use the free iCloud Drive for storage, which offers 5GB. However, when I scan through my systems, I found that Application Support/CloudDocs/session/ occupied up to 43 GB of memory space.

I once deleted it, but now I can't access any of my files and folders (though they are much more than 5GB of space). After some time, the session is reconstructed again, with 43GB. How do I fix this?

[Edited by Moderator]