How do I tell my family I don't want to see them

I've been thinking for awhile now through out my pregnancy and I know it might sound weird or harsh, but when I'm due with my baby I don't really want some of them around. Specifically my mom and grandmother. My mom in the past has been basically the most terrifying person in my life, to the point where I was in the hospital for 3 months from attempting suicide because of how she treated me. She's tried to hurt me, blackmailed and threatened nearly all the friends I had in highschool to the point they were scared to hangout with me and their parents would tell me they were sorry I couldn't be around them anymore because my mom was harassing them all to much, and even told one of my friends mom that she should kill herself because they were trying to help me after she threw me out. My mother had held me by my throat against a wall before because I waited at my friends house when I got home from school and no one came home to unlock the door for me for like 2 hours. Several occasions she had made something out of nothing, and I couldn't talk to friends and vent or she would find out somehow and I felt trapped. There's so much that happened before I got out I don't think I can type it all. And we were stationed in Hawaii at the time (her husband was in the service). I had no help from the base or the officers that had basically told me to get over it. When she threw me out I had to stay with my friend and her parents who knew what was going on and helped me contact my family back in the states to get home and when my mom found out, the last thing she said to me was that I was never going to make something of myself and she called me a whore and several other names. Now I live in FL with my boyfriend and she's been trying to talk to me again, like everything is ok between us, I've been polite and haven't went off or anything but she's been talking about taking a trip down here to see me when it's close to my due date and I can't deal with that. I get scared when I here anyone talk about her because I'm scared she might be around or when I see a truck that looks like the one she had at the time I freeze up and nearly start crying because I remember everything. I can not be around her, even if she's changed I can't do it, because over the course of my life I can only see her as part of all the worse things that have happened to me. Which she basically was.

And her mom my grandmother, is EXTREMELY religious and I care about her very much but during my time with her after my mom she forced me to go to church with her so she could use me to talk to my grandfather who was the pastor and married to another woman. Every Sunday they would ask who needed a blessing but would force me up there with those who volunteered even though I would say no, I'm not very big on religion but for letting me saying with her I figured by going it could be a way that would make her happy. But one morning when they made me go up to the alter I had said I'm fine and don't really want to go up today and my grandfather grabbed my wrist and held me in place tightly and wouldn't let me go even when I started crying. And he prayed to God to forgive me because I don't know what I'm doing.. And no one said or did anything just let him go on with it. I have bad depression and anxiety and as soon as he let me go I walked out trying to calm down but couldn't and my grandmother just went over and started talking to him like everything was fine and she knew I was crying, most of the church saw. We went home and she didn't say anything to me in the car and I didn't look at her. It took me forever to convince her that I really couldn't go back there but every Sunday morning she'd always try to talk me into it. I knew she just needed me as an excuse to talk to my grandpa, even now that I'm in a different state she asks me to write him a letter and send it to HER to give to him. Even when I told her that I was pregnant she didn't say much on it just changed the subject to writing to my grandpa, even though she knows I don't like him. My boyfriend knew about all this and planned to come get me to live with him, he drove 8 hours to pick me up. He didn't want me dealing with that and we found out my family (mom and siblings) we're moving back home to, so he came as soon as he could. My grandmother hated him and cussed him out for no real reason, I told her the day before I was leaving with him and she seemed to understand til she saw him and said she didn't trust him and that she hated how he looked and that it would be the biggest mistake of my life.

I'm sorry that this is a lot to read it's the first time I've been public about all this and I'd really like some advice, I don't want to keep my kid from family but at the same time, I can't be around them without stressing out. With my mom its like just thought of her coming here makes me want to run away from my own house. I'm terrified of her and I'm in a different state on my own and I know if she ever tried to do anything serious I could call the police or make her leave but I know I'd be to scared. And honestly I don't even think my grandmother gives a shit, and would make it about my grandpa. I normally wouldn't bother putting this up normally but part of me feels like my mom will see my profile or something and it's like that with a lot of things, I had to make a new facebook and block her immediately. I'm that terrified. Idk what to do and if you think I shouldn't let them come them how do I tell them no I don't want them around or what. I don't want to hurt my grandmother or hear my mom yell at me or try to come to my house.. I'm 19 and this is my first kid, I need some ideas please