How to file a suit for partition

I am a Hindu lady, belonging to the upper caste, and I have 2 sons and a daughter. My husband died since last 5 years. He died intestate. He had 3 properties in his name and got one of his property registered in the name of his daughters in law. Me myself out of my personal savings from my household expenses and investment purchased a 2 plot of land for myself. Now my one of my son and his wife is creating disputes and has occupied one of the property which was in the name of my husband and earlier all our family i.e. me, my other son and his family were living together. I want to file a suit for partition in the court of the law and none of my children look after my expenses and take care of my medicine. I am an old age person and also have a case history of chronic diseases, I want a concrete solution for this.