I upgraded to ios 9.2, and have lost all my contacts and gmail. Any solution?

Then add your gmail account back to your phone.

IF you sync your contacts to gmail - then select contacts after you've add the email account.

If you have your contacts sync'd with icloud you recover those.

two ways you can do it -

Settings>icloud> Toggle contacts off and back on.

or go to icloud.com and sign in with your apple id and password, then click on settings.

at the bottom right of settings youll see a link that says restore contacts, just pick your most recent contacts backup and hit restore.