BW, you are very intelligent and thankfully awake to TTATT. Sadly, you are in a no win situation. This is how the Borg destroys families. But the lesser of two evils is not getting baptized. Try to fade until your 18 then leave home, in the meantime do all the preparation you can for that. You will unlikely have any parental/family support when you leave.They will be heartbroken, but at least they won't have to shun you the rest of their lives.
I see you reaching out for support here, but your going to have to do a lot more. Explain your situation to those that can help. Go to social services, dial 211 (united way) meetup groups, even churches, schools, non cult relatives, whatever you have to, to get your ducks in a row for leaving home. There's good help out there, just don't blow it by running away and/or getting hooked on drugs.
Ok, lecture over, I don't post much, but my heart goes out to you, even though I'm not in a position to help.