Try this
.bigger {
height: 300px !important;
}
.smaller {
height: 99px !important;
margin-bottom: 2px;
}
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/css/bootstrap.min.css" integrity="sha384-Smlep5jCw/wG7hdkwQ/Z5nLIefveQRIY9nfy6xoR1uRYBtpZgI6339F5dgvm/e9B" crossorigin="anonymous">
<div class="container-fluid">
<div class="row main">
<div class="col-sm-6">
<div class="col-sm-12"><p>
1 Lorem ipsum dolor sit amet, consectetur adipisicing elit. Error nihil consequuntur itaque placeat est voluptates, temporibus iste nesciunt dignissimos excepturi.
</p> </div>
<div class="col-sm-12">
<p>
2 Lorem ipsum dolor sit amet consectetur adipisicing elit. Sint optio laudantium dolorem doloremque non praesentium sit. Corporis quisquam soluta, ullam unde deleniti at expedita facilis animi dicta facere quam iste!
</p>
</div>
</div>
<div class="col-sm-6">
<p>
3 Lorem ipsum dolor sit amet consectetur adipisicing elit. Ullam voluptas maxime eos labore, sed, temporibus tenetur a sunt ratione voluptates excepturi est eaque? Porro, nostrum impedit laborum minima quos at nulla sit officiis. Dignissimos, at. Ipsam delectus dicta ipsum cupiditate. Ullam voluptas maxime eos labore, sed, temporibus tenetur a sunt ratione voluptates excepturi est eaque? Porro, nostrum impedit laborum minima quos at nulla sit officiis. Dignissimos, at. Ipsam delectus dicta ipsum cupiditate.
</p>
</div>
</div>
</div>