ACF Gallery - Show 4 items at a time using Bootstrap 4 - advanced-custom-fields

Question

I'm using a Gallery field in WordPress ACF and I want to show a gallery only four at a time. Therefore, to achieve this, I grabbed some code for a multi-carousel in Bootstrap 4 and wanted to achieve this same effect using ACF Gallery and PHP.
Here's my code attempt:
<div class="row blog">
<div class="col-md-12">
<div id="blogCarousel" class="carousel slide" data-ride="carousel">
[...]
<!-- Carousel items -->
<div class="carousel-inner">
<?php
$images = get_sub_field('gallery');
$i = 0;
$j = 0;
$internal_counter = 0;
?>
<?php while ( $i < $gallery_size ): ?>
<?php if ( $i % 4 === 0 ): ?>
<div class="carousel-item <?php if ( $internal_counter === 0 ): echo 'active'; endif; ?>">
<div class="row">
// BEGIN this is the part where i'm stuck on
<?php for ( $j = 0; $j < count ( $images ); $j++ ): ?>
<div class="col-md-3">
<a href="<?php echo $images[$j]['url']; ?>" data-toggle="lightbox" data-gallery="dayhome-gallery">
<img src="<?php echo $images[$j]['sizes']['large']; ?>" alt="<?php echo $images[$j]['alt']; ?>" />
</a>
</div>
<?php endfor; ?>
// END this is the part where i'm stuck on
</div>
</div>
<?php $internal_counter++; ?>
<?php endif; ?>
<?php $i++; ?>
<?php endwhile; ?>
</div>
</div>
</div>
</div>
I've highlighted in comments above where I'm stuck on. Right now it's just displaying 8 pictures at a time for each carousel item such as this picture below:
Here's the desired effect I want:
So, in this particular gallery, I want to show only four pictures at a time. I was thinking of performing something like this:
<?php
if ( $j % 4 === 0 ):
break;
endif;
?>
... but it breaks immediately because I started $j to be 0 because I also need the zeroth item in the gallery.
Thanks for any help with my code.

Answer 1

SOLVED!!!
<div class="carousel-item <?php if ( $internal_counter === 0 ): echo 'active'; endif; ?>">
<div class="row">
<?php while ( $j < count( $images ) ): ?>
<div class="col-md-3">
<a href="<?php echo $images[$j]['url']; ?>" data-toggle="lightbox" data-gallery="dayhome-gallery">
<img src="<?php echo $images[$j]['sizes']['large']; ?>" alt="<?php echo $images[$j]['alt']; ?>" />
</a>
</div>
<?php if ( ++$j % 4 === 0 ): ?>
<?php break; ?>
<?php endif; ?>
<?php endwhile; ?>
</div>
</div>
I had to make sure I put ++$j to pre-iterate my variable before comparing it to a modulus of 4.