In 'Manage Websites' the main site that I use to do all changes and updates on has vanished and I can't make updates!!

In 'Manage Websites' the main site that I use to do all changes and updates on has vanished and I can't make updates!!  It has disappeared from the drop down menu and I didn't delete it. The website is functioning normally online. I'm in Mexico on vacation and freaking out a little as I own a yoga studio and cannot update classes. Please help!!