Inter-caste marriage

Have been dating my bf since 2yrs. He never committed to marry me but i always told him my intention of getting married to him and his response was i cant marry you coz m still studying it was acceptable, my parents won't agree. Later i called his parents and asked them if we want to get married after 4-5yrs will there be any issue from your end. Response of his dad was we are happy in our son's happiness. We dont have any issue you can meet. But when he came to know about my caste they got some shock and they said to him you cant even talk to her, it is never going to work, we won't allow at all. But somehow i got hurt in all these. They even threatened him if he ever talks to me or meet me they will kill him. In some argument i said to him i will end myself if you are not there. He told them and there response was go and file a complaint against her if she does something it will be on you. I mean how cheap mentality they are having, they are not even concerned about me little. He is Maratha and i am Telugu. His family wants someone from his caste. After few years of earning he may have done marriage but i spoiled it by calling his Dad. I really want to show them that caste is not the reason for rejecting proposal.