How do I go about getting emancipated?

I am 16 years old and living with my mother. I am expecting a baby in a few months. I am trying to make a life for myself and my child but my mom won't allow me to work to make money for the baby. She wants to control what I buy for my child, how I raise him, what family I have near me and him. She doesn't listen to me when I say I need to go to the doctor. I have never approved of her parenting, and never considered her a good mother. I started playing mommy to my siblings when I was 10 years old because my mom never paid attention. I don't want her to have any say in my child's life, and I'm worried that she will try to take my child away from me. She has a twisted view on reality and she can be very convincing. I just want to make sure that I can give my son the best life possible. I love my son and I don't want to lose him or give him a bad life.