Physical abuse from mother In law

Hi, I am a working woman married in the year 1993. I have a son and a daughter. I have been subjected to physical and verbal torture by my mother in law since the marriage i.e for more than 20 years till today. She does not let me meet my own parents and does not allow my children to be with them. I was even kept away from my children by my mother in law. She demanded all of my salary and I used to give it to her until I stopped recently. Never even bought a gift for my children. Worst part is she had turned my children against me and had made them abuse me too. I have never spoken up against her because one of my husband's sister was killed by her in laws and I was afraid if I did anything, I would meet the same fate. My husband used to work abroad and I never told him the situation in the house to keep him stress free. But the violence just kept increasing. I sent my son away from the city to study and be stress free and now he is back. Due to all of this, now since the past year I have moved out of the house with my husband, son and daughter to a new house. I visit my mother in law daily and provide food and check if she is okay. But again she physically abused me i.e she hit me with a broom stick multiple times. After this incident when I was at my work, I received a phone call from the police station stating that my mother in law had filed a complaint against me because I hit her. I am shocked and completely helpless now.Until now I still felt a thing for that woman but now I want justice. I cannot undo these 20 years but I want to see her punished. Please help me. Also how do such types of cases proceed? Do I have a chance at justice???