rant/advice

For as long as I've known, my dad has been a manipulative, conniving, bastard. He told me so many lies about my mother that caused me to hate her for years. I hadn't spoken to her in 5 years. Even before I was born he was violent with my mother. I never knew until I turned 10 and he choked my brother who was 8 at the time. My mother removed us from the home right away. We had to stay in shelters and transitional homes for a few years. During this time my mom and dad had gotten a divorce, and my dad had remarried. I started to get into a lot of trouble, so my mom sent my brother and I to go live with my father. She felt it would be better for us to have two adults watching over us instead of one. My dad told me she sent us because she didn't love us, and that she didn't want us anymore. He kept that lie going up until I started going to church, and I decided to reach out to my mom. I told her that I forgave her for giving us up. And she told me the truth. I have a similar situation going on now with my step mom and dad. He is filling her head with lies. Thankfully she has some sense to know that he is just trying to manipulate her. He has been abusive towards my step mom as well. She wants to leave the relationship but is so scared that he will fill their three girls heads with lies that she doesn't love them. I want to stick up for her and tell them the truth so bad but all of them are under the age of 10 and won't understand what is going on. Not only that if I speak out against him, he will ban me from seeing my sisters. I'm 20 weeks pregnant and I can't imagine not being able to see my sisters, or them not being able to see their neice or nephew. I don't want to miss out on them growing up, but at the same time I couldn't handle knowing he's doing the same thing to them that he did with me. I'm a wreck over this and I don't know what to do.