Show Meta Box Image

I’m about to pull my hair out. How do I show an image that I’ve uploaded through a meta box on the “edit page” screen?

This is my meta box code:

array(
            'id'        => "{$prefix}floorplan_attachments",
            'name'      => __('Floorplans','framework'),
            'desc'      => __('Provide the images to the floorplans.','framework'),
            'type'      => 'image_advanced',
            'max_file_uploads' => 2
        )

And this is the code that I’m trying to use to show it on the page:

$custom_image = get_post_meta( $post->ID, 'REAL_HOMES_floorplan_attachments',true);
$custom_image=wp_get_attachment_image_src( $custom_image, 'thumbnail' );
echo $custom_image;

What am I do wrong? Any help would be greatly appreciated!