Wife torture

Hi i got married 8 years it is a love and arranged marriage, were my wife hates my Mom a lot a from 4 years and have usual debate for small reasons now they stopped talking to each other from 6 months staying in one house, i have two girl kids one is 5yrs and other is 1.5 yrs both of them are as naughty with hyper active and elder trouble a lot now the younger same started now and my wife getting more stress , My wife gives lot of food for my kids were even we feel that it is more to there stomach and my wife is so stubborn that they should eat full of it if not she tortures then to by hitting them and making them cry for 1..5 hrs daily 3 times if somebody specially my mom or me interfere to stop them eating while they are crying, she becomes physic and hit my kids more and more by saying very bad words I am not able to stop her in anyways as i am afraid in my absence what she will do them same torture for 1 yr kid also if i stop her strictly the same treatment for me without any Mercy biting with teeth and nails hitting with what ever she want any place of my body ,, if i try to stop her holding her hands or slapping her she becomes more violent and show that on my kids,,,, which i cant explain how to stop her i tried so may times explainig her about her mistakes in keeping food and about my Moms good she will become voilent terrible even i get afraid by seeing her that what she will do to my kids, what i can do if i become more stubborn she wi;; say that she will die ..., I am helpless Not: we both are well educated SHE SAYS SHE WILL NOT DO OR DONE ANY MISTAKE