Friend took my signature on promissory note for 1 Lakh which he gave for investment in cryptos

Hello Sir, A friend named Ravi had transferred me an amount of Rs. 2 Lakhs to invest in Crypto currency Market 3 years ago. I made a loss of 90% and hence couldn't return the amount. Later Ravi told that out of 2 Lakh Rupees, 1 Lakh is borrowed from his friend Kishore and he is asking for money. But I said the amount is lost in trading and left with 10% of his initial investment. Ravi said that Kishore wants his money back or if I can't pay then Kishore asked to sign a promissory note for 1 Lakh. I was in a serious depression due to huge losses of my own money and others' who gave me money to invest and in that depression and out of mind, I signed the promissory note. Now after 3 years, Kishore is threatening me to return his 1 Lakh or he will serve a legal notice and file a civil case for 2 Lakh Rupees. I myself am paying 18,000 per month for a personal loan which I had taken to invest in trading and still paying the EMI. Now I am not in a position to return his money but the mistake I did is signing the promissory note. Sir, I request you to please clarify if I will loose this case or is there any chance I could get out from this? Please reply for which I would be grateful to you. Thank you!