A married woman of 44 left her husband in 2018 and living in a rented flat with her 19 yr son,

She hooked me while I was in her office for utility payment and she took my phone number and started calling me at night. Iam 70 yrs, had lost my wife in comorbidity in May 21, which I expressed her I am alone if she can help me to do ecs payment of the utility bill but she gave me some guideline paper to do in cyber Caffe. Since then she started calling me at night and I was reluctant to reply. After several call and sms she expressed her consent for intimate physical relationship. We met her in a mall and she expressed her inability to pay her rent and desire to have washing machine, geyser, mattress, oven, fan, dresses for her son for her and request me to pay rent of 5k +4 months rent due and demand a flat of 1bhk. I said all is not possible in one go, but with in one year I gave her all she wanted including 1.5L cost byke and 1.0L paid to buy his groceries for son's kirana store beside medical care of her. Till now I have spent more than 5.0L after her but she Vcall me now and then and if I don't attend she became furious and threatened me to expose me to my son and daughter with curse, fear of God and all short of abuses. We had consensual physical relationship since we met in hotels, resorts, in her flat, in my flat and other places, she is very much eager to have sex with me and if I say no to come to her flat then she came to my house (my wife died last year and my children are working outside Bengal). She is irritating me now and then and I cannot continue the relationship further with her but she would not leave me due to her more expection beside every month I give her 12-15k rupees for her rent,. Medicine andy any house hold goods. I am a retired person without Pension and facing hardship to meet her demand, I am living with my interest earned from post office saving and she donot understand that. Her son left his study after class X, and now he is running kirana store with her uncle. Now and then she ask me money for her son kirana store but now I am unable to give due to my limited financial position. Now please suggest me how I can stop her from all short threatening to disclose and her curse now and then. She is mentally ill, she has not filed divorce suit. Her son is in contact with his father. She is temporary employed in state Govt office but she claim she gets only 12 k salary and she is unable to meet all her expenses including rent of 5-7k. Out of sympathy I wanted to help her with small amount but day by day her demand has been increased. Please help me with your advice. Regards ALOKE PAL