Need a Legal Advice

Dear All, I am from Chennai and working in Abroad, One of my School mate in Chennai asked me to find some people whom he can lend money and take a certain amount of interest with monthly installments, So i referred on of my colleague who is from Mumbai, He borrowed about totally 6laks, whereas he repaid 2laks by monthly installments, and all of a sudden he lost his job and was unable to his installments as promised, So the lender calculated interest for delays and defaults and made a final amount and agreed to be paid by April 2023. But my colleague was unable to repay his dues, Meanwhile my friend(lender) is asking me to pay pending amount as he lend the borrower on my guarantee, I myself cant fulfill my own family needs how come i could pay such a huge amount, Now he has started visiting my home, insulting my father and scolding my wife over phone, and complaining to all my relative he knows, i am feeling totally helpless by being here in abroad, please can anyone help me out in this