I will never be able to be the person I want to be.

So I have been told continuously that it might be time to come out as bisexual to my parents but for me there really isn't a way to do that. Throughout my life they have always made it clear that they don't accept lgbtq people. They have also told me that if I "decided" to be anything other than straight they would kick me out and never speak to me again. I know they're serious because I've seen it happen. Some of my cousins and other close family members have come out and my parents cut them off. I'm not even allowed to contact them. I really don't know what to do, I don't want to lose the rest of my family, even if they haven't always treated me the best. Somebody help me?!