Making featured images clickable

Hello,
I want to make my featured images clickable so they would be a link to the post page. I have used the following function (in a child theme, of course).

<?php 

add_filter( 'post_thumbnail_html', 'my_post_image_html', 10, 3 );

function my_post_image_html( $html, $post_id, $post_image_id ) {

  $html = '<a href="' . get_permalink( $post_id ) . '" title="' . esc_attr( get_the_title( $post_id ) ) . '">' . $html . '</a>';
  return $html;

}

?>

The problem is that once I’m in the post, the featured image STILL link to the post page!
How do I make the featured image link behave like the post title that cancels the link once the reader is in the post page?

My blog

Thank you!