My phone is showing me iPhone storage full And I have deleted all my items and it’s still showing that and so I can’t download anything

See if anything here helps. 

Disk space - How to check the storage on your iPhone, iPad, and iPod touch.    

 Disk Space – Free Up    

 Disk Space – Free Up (2).  

 Disk Space – Free Up (3).   

 Disk Space - Free Up (4)        

 Disk Space - Free Up (5)         

I am also having the same issue! I have deleted all photos & videos (zero) but when I go to

Settings > General > iPhone Storage, the iCloud Photos still shows 56GB storage.

I rebooted the phone but still the same issue. How can we fix this?

Did you try turning off iCloud syncing, then delete the photos from the Photos app, and then delete the photos from the Recently Deleted album.