Category Name with Custom Post Type

category_name is a bit misleading, it expects the slug, not the name. Try:

$content_args = array(
    'post_type' => 'Content_Widget',
    'category_name' => $cat[0]->slug          
);

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)