Need help. It’s about my mom 😓

So this is going to be a long post so let me say sorry now!

My mom was in my life but I only saw her about once a month and she was drug addicted for 16 years of my life. She’s being going to treatment and has relapsed many many times it’s been 3 years since she’s been going and makes up reasons for why she has to start going more again instead of less (2 times a week again instead of 2 times a month). She left me when I was 15 to move back home with no telling and I started to “hate” her for it. My whole life she never raised me. My step mom has made me the women I am today along side with my dad. She told me my whole life bad things about my self and I watched her so many many suicide attempts also watched her cut herself and show me the knife she did it with. When I was around 12 she was on a drug run she got into a bad car wreck with me which wasn’t her fault but I was the only one hurt bad rushed to the ER. I told my dad later on what she was doing and she found out and told me I wasn’t her angel anymore and she never wanted to see me again which she did later on of course. So now that I’m pregnant she wants to be a part of my life more saying she can’t be the mom she is calling my baby hers. She wants to be in the room with me after I told her no she get pretty mad saying she raised me which she didn’t not even as a newborn. She cries saying she wants to be here and she’s depressed and what not. I just can’t feel sorry for her but I also don’t want to hurt her more. She’s pushing herself into a place she never cared to be before and I think it’s to late for her to think she can’t just walk into it. She says it’s not that b words place to do anything in my life (my step mom). She got mad yesterday when someone wouldn’t FaceTime her at my 3D/4D ultrasound. She later texted me sad saying something about how she just wanted to feel a part of something. She also has a ton of mental things like borderline Multi personality disorder. I think that’s all but please help I have no idea what to do. She was never really my mom before beside by blood and now she wants be given this place in my life she doesn’t deserve