Salvando dados de um form no banco

<?php
  global $wpdb;
  require('../../../wp-blog-header.php');

if(isset($_POST)) {
    $nome = $_POST['nome'];
    $email = $_POST['email'];

    $statusPost = "draft";

    $query = "INSERT INTO $wpdb->posts (post_title, post_status, post_type) VALUES (%s, %s, %s)";
    $wpdb->query($wpdb->prepare($query, $nome, $statusPost, 'slug_cpt'));

    $postid = $wpdb->insert_id;
    update_post_meta($postid, '_email', $email);
}
?>