how can I restore my lost e-mail contacts for my apple e mail. all email addresses from past year just disappeared overnight

Hello merike33,

Are you able to see the contacts on the iCloud website or a different device? If so, check out the steps for restoring contacts below found in the guide here: Restore contacts stored in iCloud on iCloud.com - Apple Support

"You can restore your contacts from an earlier version that was automatically archived in iCloud. For example, you might want to restore an earlier version of your contacts to recover some that were accidentally deleted.

When you restore an earlier version, your current version is first archived in iCloud, so if you change your mind, you can go back to it.

1. On iCloud.com, click  in the toolbar, then click Data Recovery.
2. Click Restore Contacts.

Available versions are listed by the date and time they were archived.

Tip: If you recently deleted a contact either from iCloud.com or your device that you now want to restore, it may take up to 24 hours for the archive to appear.

3. To the right of the version you want to restore, click Restore.

There may be more versions than can be displayed. Scroll to see them all.

Note: Wait until iCloud finishes restoring your contacts before you change them. During the restore process, any changes you make aren’t saved."

You can also find helpful information in the articles below.

If you accidentally deleted iCloud contacts from Contacts on Mac - Apple Support

If you accidentally deleted your calendars, bookmarks, or contacts from iCloud - Apple Support

You can also check to make sure any associated third-party accounts added have contacts enabled. The section "Temporarily stop using an account" here has helpful steps: Add contacts from iCloud, Google, and more to Contacts on Mac

If the issue remains and you're sure iCloud was used, reach out to Apple directly to further assist. Get Support

Cheers.