Someone please talk to me 😢😢

I feel like I'm going insane. Sorry this is so long but I need to get it out. So my dad is a paedophile plain and simple. He molested me at 3 and some stuff went on with my brother too. My mum still let's him come over and see the children because she believes he's blood and has a right to see them. I'm 22 weeks pregnant and made my decision to not let him have anything to do with me or my baby. I cut off all contact and blocked him on everything. My mum didn't agree with this and thought I was being selfish and heartless. I told her I don't want his to see my ultrasounds or any photos of my baby when I have her. She thinks I am putting her in a bad position by telling her not to show him any of my stuff. I love her and she's my mum but she doesn't understand. She also drinks alcohol daily so is drunk most of the time. so will forget whatever I say the next day. What do I do. My brother who is 22 also doesn't understand where I'm coming from and apparantly I'm being unreasonable because they are only photos. I don't want him in my life AT ALL. Am I being unreasonable? Am I being selfish? Someone help me.