My contacts aren't showing anymore
Have you enabled "Contact Trash and Undelete" for your site?  If so, have you tried searching in Trash for contacts? Do an Advanced search and tick the "Search in Trash" box. It will be on the right side of the Basic Criteris search pane.  Exactly where depends on what version of CiviCRM you are using - which is why I have asked for that information.

Do you have logging enabled? Can you look in the log_civicrm_contacts to see who made the last change to the contacts and when and what it was.

"Out of no where" sounds improbable. 

What has been changed on your system since you last could "see" the contacts. (Added an extension for your CMS?, upgraded?, your host changed something?)