Seu site está inacessivel note os erros :
Warning: session_start(): open(/tmp/sess_d4836b03ae0e1ca99efae65f3499a6ae, O_RDWR) failed: No space left on device (28) in /home/n9magazine/public_html/wp-content/plugins/yith-woocommerce-wishlist/class.yith-wcwl.php on line 54
Warning: session_start(): Cannot send session cookie - headers already sent by (output started at /home/n9magazine/public_html/wp-content/plugins/yith-woocommerce-wishlist/class.yith-wcwl.php:54) in /home/n9magazine/public_html/wp-content/plugins/yith-woocommerce-wishlist/class.yith-wcwl.php on line 54
Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/n9magazine/public_html/wp-content/plugins/yith-woocommerce-wishlist/class.yith-wcwl.php:54) in /home/n9magazine/public_html/wp-content/plugins/yith-woocommerce-wishlist/class.yith-wcwl.php on line 54
Warning: Cannot modify header information - headers already sent by (output started at /home/n9magazine/public_html/wp-content/plugins/yith-woocommerce-wishlist/class.yith-wcwl.php:54) in /home/n9magazine/public_html/wp-includes/pluggable.php on line 1178
Warning: Unknown: open(/tmp/sess_d4836b03ae0e1ca99efae65f3499a6ae, O_RDWR) failed: No space left on device (28) in Unknown on line 0
Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0
Primeiro tem que resolver isso amigo, e geralmente a lentidão de sites podem ser desde o servidor, plugins, imagens , temas… enfim, pra eviar é bom saber cada item que tem em seu site e sempre que mudar algo no código, notar se existe alguma difereça de desempenho.