Tristanmorrisvoiceover on "Free Theme Origami: Fatal Error Message"

My site is displaying the following message:
Fatal error: Call to undefined function wp_get_theme() in
/home/content/04/9243404/html/wp-content/themes/origami/extras/settings/settings.php
on line 10
I was trying to apply a new free theme called 'origami' when this appeared and the
site became unresponsive. I can no longer access my admin site to change anything.
I use godaddy.com with the Wordpress software. I'm not sure if there is some miscommunication between the two sites. I would be fine with completely resetting the site and starting from scratch, but I don't know how to do this.
Any help would be greatly appreciated!
Thanks
Tristan