Broken loop

<?php
            // First, let's eliminate some DRY,
            // by making an array of our categories
            $random_posts_cat_array = array( 'artists', 'projects', 'people', 'development', 'offsite', 'contact' );

            // Globalize $post,
            // since we're outside the primary loop
            global $post;
            $post_cat = get_the_category( $post->ID );
            // Current post category ID
            $post_cat_id = $post_cat->cat_ID;
            // Current post category slug
            $post_cat_slug = $post_cat->slug;

            // Now, let's find out if we're displaying
            // the category index for one of our categories
            if ( in_array( $random_posts_cat_array, $post_cat_slug ) ) {

                // Set up custom loop args
                $random_posts_query_args = array(
                    'post_per_page' => 3,
                    'orderby'       => 'rand'
                );
                // Add Cat ID to custom loop args
                foreach ( $random_posts_cat_array as $random_post_cat ) {
                if ( $post_cat_slug == $random_post_cat ) {
                    // Add Cat ID
                    $random_posts_query_args['cat'] = $post_cat_id;
                }

                // Run random posts query
                $random_posts_query = new WP_Query( $random_posts_query_args );

                // Setup random posts query loop
                if ( $random_posts_query->have_posts() ) : while ( $random_posts_query->have_posts() ) : $random_posts_query->the_post();>?>

                    <h2>Plop sticks</h2>

                    <?php foreach( get_the_category() as $cat ) echo '<div class="module ' . $cat->slug . '" data-category="' . $cat->slug . '" >'; ?>

                          <a href="<?php the_permalink()?>" title="<?php the_title(); ?>">
                          <div class="active">
                                <div class="hover"></div>
                                <?php the_post_thumbnail(); ?>
                          </div>

                         <?php
                              $sub_title=get_post_meta($post->ID,'subtitle',true);
                              if($sub_title != '') {
                              echo '<h1>'. get_the_title() .'<span> / '. $sub_title .'</span></h1>';
                              } else {
                              echo '<h1>'. get_the_title() .'</h1>';
                              }
                              ?>

                              <?php
                              // Call in the contents of a custom field called Excerpt and if custom field in admin panel is empty don't display <p> tags otherwise wrap contents in <p> tags
                              $excerpt=get_post_meta($post->ID,'Excerpt',true);
                              if($excerpt != '') {
                              echo '<p>'. $excerpt .'</p>';
                              } else {
                              echo ' ';
                              }
                              ?>
                              <p class="date"><?php the_time('YdmHi') ?></p>
                         </a>
                    </div>

                <?php endwhile; endif;

                // Be kind; rewind
                wp_reset_postdata();

            } else { ?>

                <p>There is nothing to display</p>

            <?php } ?>