Sidebar error

Hello. So, I made a really dumb mistake. I am new to WordPress and I have 17 published pages on my site. I tried to get into the code of widgets.php, but stupidly, I worked on the original desktop file instead of the one on my server and I uploaded it which replaced it. I should of downloaded widgets.php from my server. I spaced out. So, now I get this error on my page:

Fatal error: Call to undefined function: get_search_form() in /home/borrowde/public_html/iremembermovies/wp-includes/widgets.php on line 771

Here is line 771 (of widgets.php):

/**
 * Display search widget.
 *
 * @since 2.2.0
 *
 * @param array $args Widget arguments.
 */
function wp_widget_search($args) {
	extract($args);
	echo $before_widget;

	// Use current theme search form if it exists
	get_search_form();

	echo $after_widget;
}

Am I totally screwed here? Can someone please help this idiot?

Thank you

Bramble