Sum All the Post Meta of Published posts of Current Logged in user

You have to create custom query, to get data from {$wpdb->prefix}postmeta depending on the meta_key and store the meta_values inside an array, then sum them.

So we can build a function like this:

/**
* Query meta values by meta key.
* 
* @return int Returns sum of meta values
*/

function get_meta_value_by_meta_key(){
    global $wpdb;

    $metaValues = array();

    $query = "SELECT meta_value FROM $wpdb->postmeta WHERE meta_key = 'Creation_Views'";

    $results = $wpdb->get_results($query);

    if(!empty($results) && !is_null($results)){
        foreach($results as $result){
            foreach($result as $value){
                $metaValues[] = $value;
            }
        }
    }

    //get_results returns null on failure
    if(is_null($results) && WP_DEBUG == true){
        $wpdb->show_errors();
        $wpdb->print_error();
    }
    $sum = array_sum(array_map('intval', $metaValues));
    return $sum;

   }
 add_shortcode('Stats', get_meta_value_by_meta_key());