My wife is torturing my family

My self vinayak kumar.I live in faridabad,my age is 27 years old.In 2015 I did love marriage .I was in relationship with my wife since 2011, before our engagment she was ok but after the engagment she automatically change her behaviour,she fight with me 2 times.I told my parents that I will not do this marrige when my parents tried to that covience her that my son dont want to marrt you due to your bad behaviour she started to blackmail my mother if you will not fo this marrige I will do sucide so due to gear my parents convience me to marry with her,they thought if she do anything my son will go to jail .now after the marriage of one month she started to fight with me for small reason or without anyreason.I always tried convience her please dont do this .your misbehavior is showing bad impact on my family.after few month of marriage she started fight with my mother for small small reason and this continues unless my new baby born .I have son of 3.5month I am so wooried about my son and my family .when I tried to told her parents that she is doing fight every month on month. they always support her and never did try to understand her that she should not do this.now from few days she is doing blackmail I will do sucide with anyreason your whole family will go to jail,today she fight with me and she told me I will light a cylinder with fire.I am too threatened bu her blackmail and statment if she do anykind of such police and law will torure to my family .I have 3.5 month my son I am too worried about my son ,kindly suggest me what I should do ,my whole family is leaving in fear.I am also leaving in fear because I really dont know what she will do next.please please help me your alll one better advise can save my whole family life.