HELP! Entire site crashed when installing Aqua Page Builder Plugin

Hey All.. I urgently need some help to restore my site.

I was installing the Aqua Page Builder when this error message came up:

Warning: require_once(/home/[USERNAME]/public_html/wp-content/plugins/Aqua-Page-Builder-master/functions/aqpb_blocks.php) [function.require-once]: failed to open stream: No such file or directory in /home/[USERNAME]/public_html/wp-content/plugins/aqua-page-builder/aq-page-builder.php on line 42

Fatal error: require_once() [function.require]: Failed opening required ‘/home/[USERNAME]/public_html/wp-content/plugins/Aqua-Page-Builder-master/functions/aqpb_blocks.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/[USERNAME]/public_html/wp-content/plugins/aqua-page-builder/aq-page-builder.php on line 42

I am now completely unable to view or access my site. Even when I try to access WP-ADMIN page, I am greeted with this error message!

Does anyone know how I can regain access to my site.