Highlight search words in excerpt

I have designed and developed a responsive WordPress site that is almost ready for launch for a client who is an actor and producer. I have been stuck on my requirements for the search results page for three days.

My EXCERPT is far too long and includes repeated text from the Home page no matter what the search is for. Under the white links to the posts and pages for the search results, I want an excerpt of no more than 30 words which includes the search keyword (in this case the search keyword being “Ginsberg”) highlighted. So, a snippet of about 30 words, including the search term highlighted. That’s what I can’t get. When I have that, I have the search page I want.

I have spent hours Googling and searching this on Stack Exchange and Stack Overflow, as well as attempts at finding the PHP logic required myself and failing. So if there is a solution to this already here, it’s well hidden!!

WHAT I DO HAVE AND WHAT I’M HAPPY WITH IS:
Say I do a search for the Beat Poet “Ginsberg” (screen shot attached). I get a main heading saying “2 results found for “Ginsberg”. Under that a smaller heading saying “Your ‘Ginsberg search results can be found at””
then below that I get a nicely styled list of two links to the two relevant pages. I want all that. That’s great.

MY SEARCH FORM:

<div class="search-cont">                         
        <form class="searchinput" method="get" action="<?php echo home_url(); ?>" role="search">
        <input type="search" class="searchinput" placeholder="<?php echo esc_attr_x( 'Click icon or hit enter to search..', 'placeholder' ) ?>" value="<?php get_search_query() ?>" name="s" title="<?php echo esc_attr_x( 'Search for:', 'label' ) ?>" />
        <button type="submit" role="button" class="search-btn"/><i class="fa fa-search" aria-hidden="true"></i></button>
        </form>
        </div>

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MY SEARCH PAGE:

<div class="searchresultsbox"> 
                  <?php global $wp_query;?>
      <h2> <?php echo $wp_query->found_posts; ?><?php _e( ' results found for', 'locale' ); ?>: "<?php the_search_query(); ?>"</h2>
                <?php if ( have_posts() ) { ?>
            <h3><?php printf( __( 'Your "%s" search results can be found at:', 'ptpisblogging' ), get_search_query() ); ?></h3>
            <?php while ( have_posts() ) { the_post(); ?>
                 <h3><a href="<?php echo get_permalink(); ?>">
                   <?php the_title();  ?>
                 </a></h3> 
                 <?php //echo substr(get_the_excerpt(), 0, 2); ?>
                 <div class="h-readmore"> <a href="<?php //the_permalink(); ?>"></a></div>
               <?php
 $args=array('s'=>'test','order'=> 'DESC', 'posts_per_page'=>get_option('posts_per_page'));
   $query=new WP_Query($args);
  if( $query->have_posts()): 
  while( $query->have_posts()): $query->the_post();
 {
   echo $post->post_title;
   echo $post->post_content;
 }
 endwhile; 
 else:
 endif;
 ?>
 <?php } ?>
 <?php paginate_links(); ?>
        <?php } ?>
    </div>
  </div>
</div>
<param name="" value="">
                </div><!-- /searchresultsbox -->
            </div><!-- /collcelltwo -->
        </div><!-- /tb-one-row --> 
    </div><!-- /tb-one -->

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=–=-=-=-=-=-=-=-=-=-=-==-=-=-=-=-=-=-=-==-=-=-=-=-=-=-
IN ‘functions.php’

add_action( 'pre_get_posts', function( $query ) {
        // Check that it is the query we want to change: front-end search query
        if( $query->is_main_query() && ! is_admin() && $query->is_search() ) {
        // Change the query parameters
        $query->set( 'posts_per_page', 4 );
        }
        } );

I am extremely grateful for your input. Thank you!!
Keith