Sorry to hear that your Gmail contacts are missing. Follow these steps to set up contact syncing with Google Contacts:
1. Tap Settings > Mail, Contacts, Calendars > Add Account > Other > Add CardDav Account.
2. Enter the following information in the fields:
- Server: google.com
- User Name: Enter your full Google email address
- Password: Your Google account password
3. Select Next at the top of the screen to complete the setup.
After you have completed the setup, open the Contacts app on your device. Syncing should begin automatically.
Note: Make sure that SSL is enabled (under Advanced settings), and that the port is 443.
You can find the full article here:
I hope this helps get you back on track.