Harassment and mental torture by daughter

I am 67 years old. My wife had expired in 1995 and I did not remarry. I have 4 children i.e. 3 daughters and one son. My third daughter who is unmarried and about 38 years old has an affair with a person for the last 20 years. I have told her so many times to marry him or to disconnect with him but she does not listen to my advise. That person feeds her against me and she acts on his wrong advices. She mis behaves with me and does not provide me lunch & dinner in time despite of telling her again and again. I am diebetic and hypertension patient. I need food in time. I prepare my meals and wash my utensils. I am providing all facilities to her. But of no use. She often abuses me and says that if i want food in time i should re-marry. I have told her so many times that i have no objection to marry her with a person of her choice. But she neither tells the names of her boyfriend or gives his residential addresss or his father's mobile no. So i am in a fix what to do. She is well educated but behaves in a total different way without having any regard to me. Further she wants her share in my property whenever i ask her to marry. She also threatens me to harm me physically and kill herself so as to fix me in a criminal case. In such a situation kindly advise me what should i do and to whom i should approach for redressal of my greivances. I am alone in the house as my son is working out of delhi and comes only once in a fortnight.