What should I do if my loan cheque bounces and blackmail occurs?

In 2017, I took a loan of ₹1,00,000 from my friend for business purposes, for which I gave a cheque as security. The business suffered heavy losses during the COVID-19 phase, but I still repaid ₹62,000 in parts. The business closed down, but my friend presented the cheque at the bank, which bounced, leading to a case under Section 138 of the NI Act. In 2021, he started blackmailing me on WhatsApp with private pictures, threatening to share them in my office if I don’t pay. While I am attending court for Section 138 NI, I also want to pursue a civil case for blackmail and prevent the circulation of my private pictures. I seek advice on the legal draft to be submitted at the police station and to file a case in court.