Too scared to come out.

I am a closeted guy, and I can never find the courage to come out. I just really wanted to share this because I feel upset.I was born and raised in a strict Christian family. My dad is a preacher and he always tells people that gays will burn in hell. When mom caught me visiting gay porn sites, she threatened me that I should "straighten up" or else she'll tell dad. When I opened up to my sister, she was shocked and vowed to cut off our ties if I don't change.No matter how hard I try to "straighten up", I can't. I kept my gay relationships in secret and acted "like a straight guy". It's like the harder I bottle it up, the more it wants to burst out. However, I don't really want to choose between family and sexuality.I don't know what to do. I am very upset that my family, despite all of my achievements to make them proud, is ready to abandon me anytime due to my sexuality.