Hi there HTCW

Unfortunately for me I still live with my mother and every other week we have these horrible fights so negative and just hurtful (even though I no longer cry or feel pain).
Do you know much history about the home your mom grew up in when she was a child? Was there conflict in that home? Was it a loving home, or was she treated badly?
My mom grew up in a home that was unsafe for the children, because of a father who was abusive in every way. Back then, women had no rights, and there were no shelters for abused families, so there wasn't much her mother could do to change the situation. Then when my mom was 14, her mother (who did her best for her children under the circumstances) died from cancer. My mother stayed home from school for 6 months and cared for her until she died. I suspect she felt "abandoned". Her father continued to abuse her until she moved out a year or two later. The reason I share this story is because when I was growing up "there was always a crisis". My mom created mountains out of molehills. She was emotional, difficult, unreasonable, irrational and beyond frustrating at times. Conflict happened. At other times she was a good mother. Various T's over the years have explained to me that my mom grew up in a state of constant conflict. She never felt safe. Later, somehow, she married a really good man, my father. But the only thing she had ever known was conflict. So as was explained to me by T's, when life was ticking along too smoothly, that "smooth" feeling was "outside of her box" which made her uncomfortable, and she would create the next cyclone and crisis. It was a pattern. Somehow the crisis she created made her feel her within her "normal". I'm no expert, but this is how it has been explained to me. Maybe others would disagree. But it made sense to me based on my lived experience.
I'm going to go out on a limb and suggest that maybe "conflict" is your mom's normal (if this fits then it's probably also the environment she grew up in). So when things are going too smoothly, your mom gets uncomfortable, because "conflict" feels more comfortable to her than not having conflict. When my mom starts to emotionally dysregulate, she says things to "push" my buttons. I used to engage and push back. That never works but I had to learn that the hard way. I didn't know she was BPD, so I always expected my mom to behave like a normal rational human, but
now I understand she's complicated and not capable of that. I had to learn a new set of tools to manage my relationship with her, because she certainly wasn't ever going to change. I was the one who had to change. One of the things I had to learn was when she started to "push my buttons", I had to disengage and leave the situation in an unemotional way. No anger. No frustration. Just disengage and not give her the conflict, because conflict is her subconscious normal. So I had to walk away from it.
This is harder for you, because you are living with her. I live about 6 min away from my mom with my H, which made it easier to excuse myself and leave the situation. Do you have any "private" or semi-private spaces in the home apart from your bedroom, which she doesn't use much? A study? A private bathroom? Or some other space she doesn't use? A vehicle of your own? Someplace to go for a walk when you leave the house?
I thank god for him and the few wonderful people I have had in my life and moments.
It's so fantastic you have had some wonderful people and moments in your life. Hang onto those. You have found a good community here. We get it, and are here to support you.