Managed to solve it myself kinda. But the Bootstrap fade effects disappears for some reason…
Used this for the thumbnails:
<ul class="tabs">
<?php
$i = 1;
while( have_rows('my_field', 39) ): the_row();
// vars
$image = get_sub_field('thumb');
?>
<li class="tab-list">
<a href="#<?php echo $i; ?>" data-toggle="tab">
<img class="img-responsive img-rounded img-ref" src="<?php echo $image['url']; ?>" alt="<?php echo $image['alt'] ?>" />
</a>
</li>
<?php
$i++;
endwhile;
?>
</ul>
<?php endif; ?>
And this for the tabs:
<div class="tab-content">
<div class="tab-pane fade in " id="home"></div>
<?php
$i = 1;
while( have_rows('my_field', 39) ): the_row();
// vars
$text = get_sub_field('my_text');
?>
<div class="tab-pane fade" id="<?php echo $i; ?>">
<?php echo $text; ?>
</div>
<?php
$i++;
endwhile;
?>
</div>
<?php endif; ?>