AJAX call for posts through separate page

Creating an ajax more-posts options

I’m using jQuery’s load function to call information from a separate page which receives variables through $_GET, creates an $args and calls $wp_get_recent_posts

It’s obviously inappropriate to call $wp_get_recent_posts without relating the external page in some way to wordpress and it’s database but I can’t find the best way to do so

I’m getting an Internal Server Error, so the $().load is returning nothing.

My morePosts.php:

<?php
$offset = $_GET["offset"];
$to_get = $_GET["to_get"];

$args = array(
    'numberposts' => $to_get,
	'offset' => $offset,
	);

	$new_posts = wp_get_recent_posts( $args );

	for ($i = 0; $i < $to_get; $i++){
		echo '<div class="post">';
		echo '<h2>'.$new_posts[$i]["post_title"].'</h2><p>'.$new_posts[$i]["post_content"].'</p>';
		echo '</div>';
	}

?>

any help is really appreciated