I am not comfortable with my wife.. Her parents are torching me with wrong arguments.

Hello.. I am not comfortable with my wife.. Her parents are torching me with wrong arguments. We have a understanding problem since last 5 year. My wife always think i am not doing anything for her even i do everything. She trust and listen only her parents and blaming on my mother (father is death) whatever happen. My problem is she always telling lie or half matter to her parents. And her parents also taking her side without knowing the truth. And always blaming on me.. Also threatening me always because her father is in police (constable), all family member are insulting me, i am silent only because of my daughter. Now they are not even ready to separate and threatening me if anything happen to my daughter then i will see u.. you are responsible.. bla bla.. I am tired now. I have 3 year of daughter and i love her a lot. They are taking advantage of my love. They knows i can do anything for her so, always threatening me to separate me my daughter also. Please let me know how can i handle my situation. How i get custody of my daughter if we get separated. I have also a last call record proof of her father threatening me on phone. I am educated and well settle on career. My wife is also Enginner and housewife. Please guide me right way to handle my situation.