Exception Thrown, Crashed Site

I downloaded the NextGen Gallery and it made my site disappear giving an exception error “Exception thrown: not defined for ExtensibleObject”.

I went into cpanel and deleted the plugin but know the below text is at the top of my website and my dashboard.

Warning: fopen(/home3/manrico/public_html/wp-content/plugins/nextgen-gallery/nggallery.php): failed to open stream: No such file or directory in /home3/manrico/public_html/wp-includes/functions.php on line 4198

Warning: fread() expects parameter 1 to be resource, boolean given in /home3/manrico/public_html/wp-includes/functions.php on line 4201

Warning: fclose() expects parameter 1 to be resource, boolean given in /home3/manrico/public_html/wp-includes/functions.php on line 4204

PLEASE PLEASE PLEASE HELP! I am creating a website for my wife’s business.
http://www.luxehairbeautique.com

https://wordpress.org/plugins/nextgen-gallery/