iCloud. I just want to stop syncing as it's taking up my bandwidth. I can't do it. Also files from my harddrive missing in icloud drive since I disabled "Desktop & Document Folder" sync

I just paid for a 200gb subscription all I want currently is for it to stop syncing while I do some other work online. My wifi connection is slow. I will begin to sync once more when I get a faster connection.

Why when I disable "Desktop & Document Folder" sync, it takes the files I just painstaking loaded and organised on my harddrive and moves them to the 'iCloud drive'.... and make me re-download them to use them!? They were on my hard drive in the first place! Does this make sense?

... to go on, certain files that I 100% know were previously on the harddrive are now missing or no longer show up in the icloud drive?

Sorry for consternation but this makes no sense to me. Can someone kindly explain how to simply pause or stop syncing for a while. I want to leave my files on my harddrive. It should not take these away. Thanks! :)