Most contacts lost after iOS update

Hello ritasues,

Were you using iCloud Contacts prior to updating your iPhone? If so, then try these related steps:

(These steps are for iOS 16.)

1. Go to the Settings app on your iPhone.
2. Tap on [Name]
3. Tap on iCloud
4. Tap on 'Show All' (If all options do not automatically appear.)
5. Make sure iCloud Contacts is enabled.

In case they were deleted, see related steps in: If you accidentally deleted your calendars, bookmarks, or contacts from iCloud

If you were syncing contacts with another syncing service, then you'll want to follow these steps to add back your email account (if removed) and set up contacts: Manage and delete contacts on your iPhone or iPad

Let us know if this helps out or not, take care!