Were you able to recover the old ID and password? Have you signed out of the new ID and then back in with the old ID using the article below as a guide of where to sign out/in?
What to do after you change your Apple ID or password - Apple Support.
If you were syncing photos to iCloud, have you signed into Settings/Your Name/iCloud using the same Apple ID used when the photos and contacts were synced to iCloud? The iCloud sync is very, very slow. The photos sync is extremely slow. It could take several days or more for the photos to sync.
If you weren't syncing to iCloud, do you have a backup you can restore from? Restoring from a backup erases all data currently on your device. Any data newer than when the backup was made will be erased. A restore is an all or nothing restore. You can't access a back and only restore certain files.
Backup - Restore your device from an iCloud or iTunes backup.