My wife & father-in-law threatening me & my family

We have completed 6 yrs of marriage and hv a 5 yr old daughter. Since very beginning my wife had issues with all of my family members including me and started allegating against us that we don't give her proper food to it etc and torture her mentally. 2 yrs ago she with our daughter went to her parents home & threatened us from there that of we don't agree to all her demands she will file case against us so me & my father went there and brought them back agreeing to all her demands. Things actually start worsening from there. She started doing everything on her own without discussing me or my parents. Now few days ago her father came for shopping for her sister's marriage and on the day of their leaving in my absence both of them again accused my parents about no food, disrespect and verbally abused with slangs in front of my daughter. They also threatened to extort money from us by filing case against us. After reaching her own parents place she tried to communicate with me by msgs and calls but as I was pretty shaken with the incident and felt heartbroken, I didn't respond. I am under a lot of stress as I know she is not realising her fault and she'll do all these things again & again. What will happen to my daughter, me, my life.?? Please help me.