Fatal Error: Wassup Plugin

I tried to add the Wassup Plugin to my site, but in the middle of loading I got this message:

Fatal error: Cannot redeclare wassup_widget() (previously declared in /home/content/99/11451299/html/wp-content/plugins/wassup/wassup.php:4305) in /home/content/99/11451299/html/wp-content/plugins/wassup/wassup.php on line 4305

Now I can’t even get to login into my website so that I can delete the plugin and start over. Any help would be greatly appreciated!