Using WP as a CMS question

I use WP as a backend publishing tool, and use the following code to include a post and/or category in a series of PHP templates:

<?php
ini_set (user_agent, "blah");ini_set (default_socket_timeout, "5");
error_reporting(0);
$theurl="https://www.theurl.com/blog/2007/11/02/the-post-or-category-slug/";
$filestring=file_get_contents("$theurl");
echo "$filestring";
?>

You can see this working here: https://test.naturopathy-uk.com/home/main/ – each area on the page calls a different post or category of posts.

This works just fine, but it’s creating a real load on Apache server, especially when there are several instances of this call to include content from WP, as is most always the case. I can’t use a simple:

<?php include(); ?>

as my host says no, security-wise. Does anyone have any suggestions regarding this? Can the Loop be used to include multiple instances of specific posts and/or categories in the same page and, if so, would this be just as much of a resource hog as what I’m doing here?

I should mention that the WP install sits in the directory as above i.e. https://www.theurl.com/blog/.

Many thanks for any help, looking for a more elegant way of doing this.

Best,

– Rob