All my old videos are gone.

My old videos are gone from photos. I didn’t delete them. All the older pictures are there but the videos are gone. Is there any way I can retrieve them. This is not good if older videos are getting deleted by itself. I have a lot of storage in my iPhone plus I pay for iCloud storage. I had lots of old videos they are gone. I didn’t notice it until today. Can anyone help me here please?

Thank you!

Forhad