Half of my entire camera roll has just gone, I’ve done all the steps usually asked by Apple like the iCloud is on there not in recently deleted or in hidden

Hello there Dxisymxrie.

Thanks for reaching out to the Apple Support Communities! If you still have issues with missing photos after following the steps in the article If you're missing photos or videos in the Photos app, we would recommend reaching out to Apple directly by checking out this link to Get Support and they will be more than happy to proceed with additional steps.

We wish you the best of luck!