Can’t load videos or photos on my iPhone

• Make sure you remove all the photos and videos from your Photos App Recently Deleted photo album
• Toggle on Optimize Photos for your device’s iCloud Photos setting
• Restart your device after deleting items to free up storage
• Update your device’s iOS or iPadOS to the latest version–use iTunes or Finder if you have a computer

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)   -  

https://www.youtube.com/watch?v=bnhuHSv_WrI