I would be in the "dont do it" camp but I am not a 15 year old trapped in the situation you are in. I am 30+ who lives my own life.
Do what you need to do to survive but make the commitment that you will get out. Sometimes at such a young age we cannot see past tomorrow, next week or even next year. Baptised or not, you will get through this. You will face consequences both ways. The very fact that you are on this website shows that you are worlds away from where I was when I was 15. I had no idea there was life outside the bubble. You do and it is great! Buy your time, firm your resolve and do whatever you need to do to survive.
If you have to get baptized you will face very real consequences. If you dont get baptized you will face consequences. Be true to yourself always even if you have to "play a role" for others. Most importantly, remember that tomorrow is always coming, you have options, you will make new friends and you will get through this!
I do not know you but please know that you are loved.
pbrow