Wife torturing husband

I met my wife in October 2014. We met through a matrimonial website. After meeting for few times we decided that we are the best match for each other. Out parents met and we got married in January 2015. I live with my mother in gurgaon and after marriage we started living there. My wife's office is in delhi near ITO. It was quite difficult for her to travel all the way there so After 1.5 months of our marriage my wife said my mother doesn't like her and doesnt treat her well so we should move to a rented apartment in delhi i did what she asked for. In few months she started fighting on small pety issues as why have i bought crate of eggs when we only need few. For instance i went to a pan shop to cigarettes she asked me to buy a coke for her i did. I ordered a pan and when i came back to my car she started abusing me why dint I bought her a pan. I tried explaining her let me go and buy one for her but she started screaming and tried to jump of the running car. This is not the first time this kind of thing happened. Whenever we have an argument or fight she starts hitting herself or will throw stuff here and there. Or will take a knife and threaten me that she will kill herself. I have asked her if it is so difficult for both of us to live together why dont we separate. But she says she will kill herself if i leave her. I dont know how to get this sorted as it is ruining both of our lives. Kindly help Gopal