iCloud not working on Systems Preferences

I don't know why these things keep happening:

1. Can't log out of my iCloud on Mac. When I do, it prompts me to type in my password to turn off Find My Mac but it just keeps loading for hours.

2. I try to set up the iCloud Drive Desktop and Documents Folder by clicking it but it's stuck at loading for a few hours now.

3. Same issue whenever System Preferences prompts me to type in my password/do anything with my iCloud account and it just gets stuck loading.

Help?

ETA: somehow I posted this on the wrong place because my mac is running on sierra (10,12.6) but i'm not authorised to edit my own post, so.

最后更新：2017-09-08 12:42:52