This person attacking you is a souless monster. There's no other way to describe someone with this much ugliness and jealousy in their heart. Rest assured she's being eaten alive by her own hatred and negativity. There's nothing you can say or do to appease her, she'll continue to try to drag you down to lift herself up because she knows she's got nothing meaningful to say in her own right. All you can do is try to detach yourself by realising that while you're the focus of her diseased mind, it's not really about you. Karma will do its work.