Function that get the total number of conversations for the current user

add_action( 'better_messages_before_new_thread', 'custom_restrict_new_thread', 10, 2 );
function custom_restrict_new_thread( &$args, &$errors ){
    // User who creating thread
    $user_id = get_current_user_id();

    // Get array with recipients user ids, which user trying to start conversation with
    $recipients = $args['recipients'];

    /**
     * Your logic to determine if this user can create thread
     */

if（$user_id=1){ // limit this userid 1
    if($total_numberof_conversations>3){
        $can_create_thread = false;
    }else{
        $can_create_thread = true;
    }
}else{ // other users can create new thread
    $can_create_thread = true;
}


    if( ! $can_create_thread ){
        /**
         *  Adding error which will be shown to user
         */
        $errors['uniqueErrorSlug'] = 'You cant start new thread now.';
    }
}

I need a function that output $total_numberof_conversations for the current user, can you advice? thank you very much.