My Narcissistic husband latest disaster?

He insisted on inviting my mom to stay with us for a few months ( we have a toddler and I had an emergency operation) . He wouldn't tolerate her ( she is not an angel she is still recovering from depression after my uncle's suicide a year ago) my husband won't go easy on her, constantly checking her bathroom, bedroom , to clean like a freak, having anger outbursts and acting like a jerk over the slightest thing, my brother came to stay for a few days and to take get back ( they live in another country) . My husband was an absolute jerk again to the point that he had an argument with my brother. Needles to say they left and stayed fir a hotel and changed their departure date . My husband now wants me to cut ties with them. And to forbid them from seeing my daughter. Why dont narcissists just end their lives and give us the relief we deserve . They don't deserve to live like everyone else. The amount of pain they cause is unbearable 💔 and they are not sick to look for a cure. They are just pure evil