How do I disable AddThis buttons on excerpts via the source code

I am NOT using the AddThis plugin because I already have enough plugins as it is. Instead I added the code below. But now these buttons are also showing on my home page which have excerpts. I only want the buttons to show on the full post. But I do not know how to EXCLUDE them from the excerpts. I don’t know any php.

Can anyone help? Thanks! Kerstin

URL: http://deardietmonster.com

Code in _post-footer.php file:

<?php wp_link_pages( ‘before=<div class=”page-links”>Page:&after=</div>’ ); ?>

<!– AddThis Button BEGIN –>
<div class=”addthis_toolbox addthis_default_style addthis_32x32_style”>
<img src=”http://deardietmonster.com/wp-includes/images/social/facebook.png&#8221; height=30 width=30>
<img src=”http://deardietmonster.com/wp-includes/images/social/twitter.png&#8221; height=30 width=30>
<img src=”http://deardietmonster.com/wp-includes/images/social/pinterest.png&#8221; height=30 width=30>
<img src=”http://deardietmonster.com/wp-includes/images/social/email.png&#8221; height=30 width=30>
<img src=”http://deardietmonster.com/wp-includes/images/social/addthis.png&#8221; height=30 width=30>
</div>
<script type=”text/javascript”>var addthis_config = {“data_track_addressbar”:true};</script>
<script type=”text/javascript” src=”//s7.addthis.com/js/300/addthis_widget.js#pubid=ra-538780dc381e0561″></script>
<!– AddThis Button END –>

<?php if ( ! duet_option( ‘hide_categories’ ) ) : ?>
<?php if ( has_category() ) : ?>
<div class=”cat-links”><?php _e( ‘Categories: ‘, ‘duet’ ); ?><?php the_category( ‘, ‘ ); ?></div>
<?php endif; ?>
<?php endif; ?>

<?php if ( ! duet_option( ‘hide_tags’ ) ) : ?>
<?php if ( has_tag() ) : ?>
<div class=”tag-links”><p><?php the_tags( ‘Tagged: ‘ ); ?></p></div>
<?php endif; ?>
<?php endif; ?><!– [end] footer –>