Foreach is not iterating properly /with wordpress

I am trying to iterate through three recent posts and display their thumbnail, title and permalink.

The first one has a slightly different look so there is an if statement as well to display the first one in a different setting and then iterate throguh the rest. What is happening instead, it is showing the first post three times with styling for both if and else.

I am not sure what am I doing wrong, thanks for any help!

<?php
      $recent =  wp_get_recent_posts( array('numberposts' => 3) );
        $i = 0;
        global $recent_post;
        foreach( $recent as $recent_post ) {
          if ($i == 0 ): ?>
              <div class="header_recent main">
                <a href="<?php the_permalink($recent_post); ?>">
                  <img src="<?php echo get_the_post_thumbnail($recent_post->ID); ?>"/>
                  <div class="overlay">
                    <h1><?php the_title_attribute($recent_post); ?></h1>
                  </div>
                </a>
              </div>
      <?php else: ?>
          <div class="header_recent side">
            <a href="<?php the_permalink($recent_post); ?>" title="<?php the_title_attribute($recent_post); ?>">
            <img src="<?php echo get_the_post_thumbnail($recent_post->ID); ?>"/>
                <div class="overlay">
                  <h1><?php the_title_attribute($recent_post); ?></h1>
                </div>
          </div>
    <?php endif; $i++; }
  wp_reset_postdata(); ?>

Also, I would really appreciate help with the warning about get_the_post_thumbnail function:
Notice: Trying to get property of non-object on line 29