What do you do when that's all you care about anymore, all that your life has become?

I just want to feel safe. I probably am, but I don't feel it. I always feel threatened at home, my dad's presence is enough just to put me on edge constantly, so much so I'm just accustomed to it now. He's not even violent anymore and hasn't been for years but I still feel unsafe. I'm so 'used' to it I barely even notice the instinctual twinge of anxiety I get when I hear his voice or footsteps or anything.

But somehow it's reduced me to tears. I love this home and I love my mum and my sister. But I just want him out of my life. I don't know what to do. I can't even kill myself because he's said he would copy me so I'm trapped in this world of fear.