Hi there stillparker,
It sounds like you wish to turn off iCloud Photos, but keep seeing a prompt that it is busy and cannot be turned off.
It could be because iCloud Photos is currently syncing photos. You may need to wait until those are finished syncing before turning off iCloud Photos. Please also see the information below, which might be helpful before turning off iCloud Photos:
Before you turn off iCloud Photos
Before you turn off iCloud Photos, make sure that you have all of your original photos and videos on your device. To download the original photos and videos:
* On your iPhone or iPad, go to Settings > [your name] > iCloud > Photos and select Download and Keep Originals. Keep your device plugged in to power and connected to the internet.
* On your Mac, open Photos, choose Photos > Settings (or Photos > Preferences), then click iCloud and select Download Originals to this Mac. Keep your Mac plugged in to power and connected to the internet.
* On your PC, learn how to download photos and videos from iCloud Photos.
You can also select the photos and videos that you want to download from iCloud.com. After your originals download, you can turn off iCloud Photos and new changes like uploads of new photos, edits, and deletions will no longer sync across your devices.
That information, and more, can be found in this article: How to turn off iCloud Photos
Take care!