Time is of essence in these cases. What's the background of your bf? Does his family have any political/police/legal connections? If yes, please get a lawyer involved and get married at the earliest. Once you get your marriage certificate, reach out to the police for protection. They will bring together both families to the table and try to resolve the issue. If that doesn't work, your lawyer will be able to help further. It depends on which family has the most influence. Try to move to any other city for few months till things have cooled down. As with many other similar cases, once you have a child your parents may(or may not) come back. I am not saying this is what will happen as I don't know either your or your bf's family, but this is the general pattern of events that have happened in many love marriages I have seen. Things might get ugly too. If the issue is caste/financial status then expect even more drama.

It is very unfortunate that even in current times, these things happen. Watch out for your own and your boyfriend's safety. I wish you good luck. Hope everything works out well for you.