Custom Form Conctact In Wordpress and Ajax

<?php
/**
 * The template for gym contact form.
 * @link https://developer.wordpress.org/reference/functions/wp_nonce_field/
 */

if ( ! defined( 'ABSPATH' ) ) exit;

$response = "";

//response messages
$not_human       = "Human verification incorrect.";
$missing_content = "Please supply all information.";
$email_invalid   = "Email Address Invalid.";
$message_unsent  = "Message was not sent. Try Again.";
$message_sent    = "Thanks! Your message has been sent.";


//user posted variables
//$name = isset ($_POST['message_name'])? esc_sql(sanitize_text_field($_POST['message_name'])):"";
//$email = isset($_POST['message_email'])? esc_sql(sanitize_text_field(sanitize_email($_POST['message_email']))):"";
//$phone = isset($_POST['message_phone'])? esc_sql(sanitize_text_field($_POST['message_phone'])):"";
//$message = isset($_POST['message_text'])? esc_sql(sanitize_text_field($_POST['message_text'])):"";

//$human = $_POST['message_human'];

//php mailer variables
function my_contact_form(){
if (isset($_POST['gymclub_nonce_field']) && wp_verify_nonce( $_POST['gymclub_nonce_field'], 'custom_action_nonce')){

         $to = get_option('gym_contact_admin_email');
         $name     = sanitize_text_field($_POST['message_name']);
         $email    = sanitize_email($_POST['message_email']);
         $phone    = sanitize_text_field($_POST['message_phone']);
         $message    = wp_kses_data($_POST['message_text']);
         $subject = "Someone sent a message from " . get_bloginfo('name');

         $headers = 'From: '. $name . ' <' . $email . '>' .
         $sent = wp_mail( $to, $subject, $message, $headers );

           if ($sent){

            $r = array(
                  'name'  => $name,
                  'email' => $email,
                  'phone' => $phone,
                  'message' => $message,
                  'time' => current_time( 'mysql' )
            );
             wp_send_json_success($r);
           } else {
            $r = array('message' => 'Mail Error');
            wp_send_json_error($r);
           }

    }
       $r = array('message' => 'Validate Error' );
           wp_send_json_error($r);

   }

// WordPress Ajax
add_action( 'wp_ajax_my_contact', 'my_contact_form' );
add_action( 'wp_ajax_nopriv_my_contact', 'my_contact_form' );


//function to generate response
function my_contact_form_generate_response($type, $message) {
   global $response;

  if( $type == "success" ) {
    $response = "<div class='alert alert-success'>{$message}</div>";
  }
  else {
    $response = "<div class='alert alert-danger'>{$message}</div>";
  }
}

// On send - works but prob not best practice https://codex.wordpress.org/Plugin_API/Action_Reference/admin_post_(action)
 if (!empty($_POST) && !empty($_POST['g-recaptcha-response'])) {
  //validate email
 if(!filter_var($email, FILTER_VALIDATE_EMAIL)) {
   my_contact_form_generate_response("error", $email_invalid);
   }
   else {
    //validate presence of name and message
    if(empty($message || empty($email))) {
      my_contact_form_generate_response("error", $missing_content);
     }
   else {
     $sent = wp_mail($to, $subject, strip_tags($message), $headers);

    gym_contact_create_entry($name, $email, $phone, $message );

    if($sent) {
       my_contact_form_generate_response("success", $message_sent); //message sent!
      }
     else {
       my_contact_form_generate_response("error", $message_unsent); //message wasn't sent
     }
   }
  }
 }
 else {
   if ( empty($_POST['g-recaptcha-response']) ) {
      // Recaptcha fail
       my_contact_form_generate_response("error", 'Are you a robot?');
  }
}

function gym_contact_create_entry($name, $email, $phone, $message ) {
  global $wpdb;
  $table_name = $wpdb->prefix . 'contact';

  $wpdb->insert(
        $table_name,
        array(
            'name' => $name,
            'email' => $email,
            'phone' => $phone,
            'message' => $message,
            'time' => current_time( 'mysql' )
        )
    );
}

get_header(); ?>

<?php
// Get address defaults
$c_addr_1 = get_post_meta(get_the_ID(), '_contact_addr_1', true);
$c_addr_2 = get_post_meta(get_the_ID(), '_contact_addr_2', true);
$c_addr = trim( $c_addr_1 . ' ' . $c_addr_2 );

// Get phone default
$c_tel = get_post_meta(get_the_ID(), '_contact_phone', true);

// Get email default
$c_email = get_post_meta(get_the_ID(), '_contact_email', true);

// Get text defaults
$c_text_1 = get_post_meta(get_the_ID(), '_contact_text_1', true);
$c_text_2 = get_post_meta(get_the_ID(), '_contact_text_2', true);




?>

<script src="https://www.google.com/recaptcha/api.js" async defer></script>

<div class="container">
  <div class="contact">
    <div class="col-md-6 col-md-offset-3">
      <div class="form-area">
              <div class="text-center contact-h"><?php the_title();?></div>
            <?php echo $response; ?>
            <form id="contact-form" action="<?php the_permalink(); ?>" method="post">
                  <div class="group form-group">
                      <input class="form-control" id="name" type="text" name="message_name" value="<?php if (isset($_POST['message_name'])) { echo esc_attr($_POST['message_name']);} ?>">
                      <span class="highlight"></span>
                      <span class="bar"></span>
                      <label for="name">Name</label>
                  </div><!-- end div group form-group -->
                  <div class="group form-group">
                      <input class="form-control"  id="email" type="email" name="message_email" value="<?php if (isset($_POST['message_email'])) { echo esc_attr($_POST['message_email']);} ?>">
                      <span class="highlight"></span>
                      <span class="bar"></span>
                      <label for="message_email">Email</label>
                  </div><!-- end div group form-group -->
                  <div class="group form-group">
                      <input class="form-control"  id="phone" type="tel" name="message_phone" value="<?php if (isset($_POST['message_phone'])) { echo esc_attr( $_POST['message_phone']); } ?>">
                      <span class="highlight"></span>
                      <span class="bar"></span>
                      <label for="message_phone">Phone</label>
                  </div><!-- end div group form-group -->
                  <div class="group form-group">
                      <div class="text-group">
                          <textarea class="form-control" type="text" name="message_text" rows="4"><?php if (isset($_POST['message_text'])) { echo esc_textarea($_POST['message_text']); } ?></textarea>
                          <label for="message_text" class="input-label">Message</label>
                          <i class="bar"></i>
                      </div><!-- end div text-group -->
                  </div><!-- end div group form-group -->
                  <div class="g-recaptcha" data-sitekey="6Ld61NkUAAAAAJJ60gH6Ku38xJwj8nzKWbYiaecs"></div>
                  <input type="hidden" name="submitted" value="1">
                  <?php wp_nonce_field( 'custom_action_nonce', 'gymclub_nonce_field' ); ?>
                  <button class="btn btn-primary" id="submit" type="submit" id="gymclub-submit" name="submit">Send</button>
            </form><!-- end form -->
      </div><!--end respond -->
   </div><!-- end div -->
 </div><!-- end div contact -->
</div><!-- end container -->
<?php get_footer();