Want to marry a boy of different cast. Parents threatening to kill me.

i also live in separate from them but they come at my room with relative to do marry otherwise we will kill you .my father also use abusive language for me as same as my mother .i totally depressed no one with me and no one get ready to help me they thought i am wrong .because i want to marry a boy who is not same cast this is the main problem of him so i said okey you can not agree this i also can not marriage to other. live me alone but they called me and use abusive language .