My mom has NPD and I’m scared to go back home.

My mom has npd like examples of it. She’s nice and lovebombs me in text messages. Tells me to come back home to live, visit and I promise you if I came there tomorrow she would be nice maybe half the day. The. She would randomly yell at me. I’ll probably be sleeping on the floor so she can humiliate me and step over me while I’m sleeping. Her whole mood will change. She had me at 19 and she doesn’t see me as a daughter more like competition I called her for support about being abused by my ex even showed her my black eye, but she quickly reverts the topic back to her and how she’s graduating online college. I’m like aww that’s nice you get to graduate cause nobody kicked you out at 17 years old when you were in college, the miliatary and beauty school. Like she did me. I think she gets a kick out of knowing that my life is tuff right now. She’s taking care of my grandma who has dementia and I really want to see my grandma but I’m scared to go cause my mom will find a way to pick a fight with me and hurt my feelings. Also my mom found my step dad who pretends and enables her so if me and my mom fall out my step dad will say “what happen why did you just up and leave ? Did we do something wrong “ because the last time she was so bad I ran off with my ex husband and just left the state. Cause my mom was literally bullying mw and harassing me in text saying mean things to me, and calling me the b word. She is a bully and it’s funny because no matter how nice of a daughter I am and how careful I am with my words she will snap mid conversation. She’s the real mental patient.