Education loan guarantor defaulting despite payment completion

Hi, I'm 32 and working. During my MBA which was part sponsored/scholarship my father was a bank manager and decided to get me a loan and signed as guarantor. He asked me for necessary documents and went on with processing the same from bank. After my MBA completion I got my job and wanted to pay off the loan but my father was not happy because I had decided to marry a girl outside our caste. Despite many attempts my father did not agree to the marriage but threatened to kill me and my going to be wife. I tried many times to get the loan transferred to my salary account as ECS mandate but my father did not give me the loan details and kept the ECS mandate to his account. He promised me to pay off loans and I trusted him blindly. I kept giving my emis to my father by cash but he would continuously default and I was unaware. Now after 6 years he has defaulted over 25 times and really ruined my cibil score. I did pay all my loan dues to him. The bank never contacted me regarding the default and I never received any message regarding the loan from the bank on my phone and neither did the bank give any calls. Again in 2019 Nov after 5 years I got to know while applying for a loan that he had made so many defaults in payment. As of date, I have not received any information on the loan from the bank and my cibil score and eligibility for future loans is ruined. Please provide me legal action against my greedy and dubious father to be taken and against the bank for negligence and ruining my cibil. As it will be a bad strike for any future financial situation.