How to handle family opposition and threats regarding interfaith marriage?

I have been in love with a guy for 9 years. He is Hindu, and I am Christian. He is currently working as a probationary officer in a finance firm, and I am a civil services aspirant. I convinced my family for our marriage, but his family is not convinced, even after he has tried many times. They are threatening him with suicide if he marries me. His mother once attempted suicide. He is now very frightened and doesn’t want to lose any of his family members. He is going through mental trauma. My family wants to support him, but due to these threats, he is not ready to marry me. We are in a dilemma and don’t understand how to proceed further. He has been strong enough until now, but because of the circumstances, he is at a breaking point. Can you please guide us on how to handle this situation?