Sorry. I’ve just looked at this further and it looks like you are messing up the two methods as mentioned in this page? http://www.advancedcustomfields.com/resources/relationship/
So the foreach you have used in your original code doesn’t need the <?php wp_reset_postdata(); ?> so you could remove that or you could use the first method in the linked example but you would have to restructure your $post and $p variable names.
Hope this helps!
