How to recover disappeared iCloud videos?

Videos and photos in iCloud are only changed when actioned by the user. Did you delete the videos anywhere else? That would be the only cause of videos being deleted. If the videos/pictures are not in iCloud or on your device, they no longer exist. You can always restore from your backup(s) that you keep elsewhere using Time Machine or similar.

aidana19 wrote: …Today, after two days, everything has disappeared completely — all the videos from the past 10 years, including the entire history of my child growing up.

This is truly awful! Unfortunately, it's too easy on a touch screen to accidentally select extra pictures or tap a wrong button. One thing we see is that people mix pictures from iCloud with transfers from a computer, and those two things are incompatible--usually there are warnings. Also, we see disasters happen from 3rd party apps, especially those promising to "clean" or "speed up" the phone. In any case, we can't know exactly what happed in your case.

That's why Apple ( and we here ) recommend keeping back up copies of precious memories and files. Since you use a MacBook, if it's connected to iCloud Photos, then backing up the Mac backs up the pictures. Using Time Machine with an external drive is a good way to keep files safe.

We've all had losseson our computers-- we're so sorry that yours is an especially sad one.

It sounds like you may have had incomplete synchronization between your devices and iCloud. You’ll need to restore from your Time Machine (or similar) backup.

No one from Apple is going to see this post. Apple does not participate here. This is strictly a user forum.

aidana19 wrote:

I don’t have Time Machine 😭

I'd recommend backing up your data, especially if it is important to you. iCloud is primarily a synchronization service, not a backup.

The only solution is to restore from your backup. Having no backup means no recovery.