Money lent

I have taken 3 lakhs from a person and written a bond with a period of 3 years for the interest of 5 rupees. I have nearly one lakh interest for some time. And unable to pay from last two years. She sent a lawyer notice that I need to pay 16 lakhs immediately otherwise I need to register my land on her name. Also she has taken 3 lakhs from my father and added to her interest account. But my father thinking that still she is paying interest to me. But it is not the case here. I am neither able to say truth to my father nor able to pay 16 lakhs. What should I do now?? Please give me some suggestion.