I will start with this, never pass raw variables to a sql query! unless you have 100% control over the variable content, and even then I would still not pass it raw.
Always use prepare().
Now going by your need you will need to do something like this
<?php
$paged = (get_query_var( 'paged')) ? get_query_var('paged') : 1;
$posts = new WP_Query([
'post_type' => 'post',
'posts_per_page' => 1,
'post_status' => 'publish',
'meta_key' => 'Mytitle',
'meta_value' => $mytitle,
'meta_compare' => 'LIKE',
'paged' => $paged
]);
?>
<ul>
<?php if ($posts->have_posts()) : while ($posts->have_posts()) : $posts->the_post(); ?>
<li><?php the_title(); ?></li>
<?php
endwhile; endif;
wp_reset_postdata();
?>
</ul>
<div class="pagination">
<?php
echo paginate_links([
'base' => str_replace(999999999, '%#%', esc_url(get_pagenum_link(999999999))),
'total' => $posts->max_num_pages,
'current' => max( 1, get_query_var('paged')),
'format' => '?paged=%#%',
'show_all' => false,
'type' => 'plain',
'end_size' => 2,
'mid_size' => 1,
'prev_next' => true,
'prev_text' => sprintf('<i></i> %1$s', __('Newer Posts', 'text-domain')),
'next_text' => sprintf('%1$s <i></i>', __('Older Posts', 'text-domain')),
'add_args' => false,
'add_fragment' => '',
]);
?>
</div>
This is a very raw example so you will need to do changes based on your needs.
Some resources to get a better idea on how everything works.