Iphone and Icloud storage
I added space to the cloud because my iphone is out of storage. My phone is backed up and now I can't safely delete photos from the phone without deleting from the cloud too.
It’s correct that if you delete photo’s on your iphone, they’re deleted in iCloud too, because it’s a sync service. Optimizing storage on your iPhone can help.
Try to free up space on youriphone as storage on your iPhone is not the same as iCloud storage
https://support.apple.com/en-us/HT201656
Optimizing photo storage on your iPhone can help a lot
https://support.apple.com/en-us/HT205703