Girl is harassing/blackmailing me

I'm a married man located in Mumbai. Recently I got information of one site where we get the numbers of female escorts and girls who r ready to do services for you. For just a curiosity I had browsed the site and come across one or two numbers of female escorts. I thought that might be fake so just messaged them on Whatsapp. I got a reaponses but later I had ignored them. For one escort, she had provided some seducing pictures and thinking that she may be a fake contact I responded with some naughty chats and told her we can meet in a week which I had not done. Everything was okay till week and suddenly on 19th Mar I got message from her asking why m not responding and bla bla. To get rid of it I just ignore and responded with harsh language "fuck off". On that response she started threatening me that she will message or post chat on my FB account where she is not in my friend list and also provide same to my wife. Initially I had ignored her but in sometime she had posted the screenshot of our chat on one of my FB photo and also sent friend request to my wife. On which I had requested her not to do so and apologize. She asked me to transfer 3000 rupees in her Paytm account and she will forget all. As I was afraid and not having idea at that time I had transferred amount. For 1 day it is all normal but again on 20th she messaged me on whatsapp saying she want 5000 more or else again she will post our chat on FB. I told her that it is impossible for me. On that she had given time till 23rd of Mar 2017 and asked me to get some clients for her service, asking me to do mouth publicity. I had asked for help to my friends but they suggested it is fake account and do not respond. I had done same and blocked her on whatsapp and FB. I thought now it has been settled but on 25th she started messaging me sms and calling me but I had not responded. Also threatened me on email that if I had not replied to her message she will fwd chat to my relatives who are in the FB. Later on same night she posted our chat on one my friend's photo in which I was tagged. I had removed the comments but she tried calling me in the night with different number come to know with true caller app. I had asked one of my friend if it is okay to lodge police complaint but he suggested not to do so as I will get involved and police will take legal actions on me too as I'm married and I'm doing this things. Please help me or suggest me what to do in this case . Till now my wife and my family is unaware of this thing but I'm afraid what they will think about me if they come to know. Also I forgot to mention that her phone number never connects whenever me and my friends tried to call.