I can’t log in to my website

I can’t log in to my website.
I cleared the site of data early on, because that’s what my boss told me to do. I thought we wouldn’t use it anymore. Now my boss has determined that the site is needed after all, and I am to restore everything. I have a backup, but there is no way to log into the site anymore.
http://www.reinigungskraft-dresden.com
I am very much asking for help, otherwise I will be fired.

Die Seite, für die ich Hilfe brauche: [Anmelden, um den Link zu sehen]