MY Photos gone

Please check the following

1. Did you have backup (iTunes or iClouds), --> Restore your iPhone, iPad, or iPod touch from a backup ...
   1. iCloud backup doesn’t include information already stored in iCloud, like Contacts, Calendars, Bookmarks, Mail, Notes, Voice Memos, shared photos, iCloud Photos*, Health data, call history, and files you store in iCloud Drive.
   2. *-If you had turned on iCloud Photos, your content is automatically stored in iCloud. 
2. Did you sync with iCloud earlier and now it is disabled. Then again --> Set up iCloud on your iPhone, iPad, or iPod touch - Apple ...
3. Have you ever imported your photos to Mac/PC --? Use Photos on your Mac - Apple Support OR Set up and use iCloud Photos on your Windows PC - Apple ...
4. Have you ever uploaded them to any Drives (OnDrive, Drive, Flickr, DropBox) - Back up iPhone data with Google Drive - iPhone & iPad ...

Check the followings:

1. https://www.icloud.com with your apple ID credentials that you have used on your iPhone
2. Have you backed-up your iPhone with Mac/PC
3. Have you imported your Photos/Videos to Mac/PC
4. Have you synced your Photos to Google Photos
5. Have you uploaded your Photos to third party Photos Applications: Flickr, Google Photos etc
6. have you shared your photos with families and friends using Shared Albums
7. Have you hidden your photos, just open the "Hidden" folder in the "Albums" tab, in Other Albums Section.
8. have you deleted your photos, Check Recently deleted folders on your iPhone under Photos / Albums [Scroll Down]