Very sorry to hear that. My mom can be mean but she's never been cruel. While she is in the throes of a swing it's like not only does she not have control of the rage or emotion but she doesn't realize it's not a normal reaction to whatever scenario. She's never beat me (aside from a few spankings that got a little out of hand, I remember at about 4 holding my arm and going into the basement and crying to my big brothers who ran a cloth under some cold water and made me a toddler tourniquet, it wasn't broken or anything just stung and that's kid logic) or called me fat (which as a kid, would have been a great burn as I already had issues with food and binging/starving) and she never killed my pets in my face or anything but she could just go from ice cold to boiling point in no time. For instance, when I was 16 my boyfriend at the time and I took a break, she immediately went into a tirade about my being a slut and that's why I couldn't keep a man and that I was going about relationships the wrong way. The fellow and I dated since 15, I made him wait 5 or 6 months before we had sex and we got back together until I was 20. Just things like that. It's like she didn't mean to call me a slut, but she did it out of concern and anger and it was like she was seeing a scenario in her own life played out. She's since apologized for it and implying I was promiscuous. Hell. Even through the breaks with the ex at 24 I've only had 4 partners and I've been single for 4 years xD I thank you for your story though there are some tones that resonate like the speeding while the child is in the car. As a kid I didn't want to tell her about an abusive bf of hers because I felt like I'd get blamed for luring him and my brother and being a succubus. I was 6 or 7. I wasn't the adult. Nor was my brother. She recently, quietly and supportively questioned that period. She seems apologetic and genuinely broken hearted. I didn't have the heart to come clean about the abuse so I vehemently denied it but said "if it did happen, it's blocked out and I'd prefer we leave it that way." That's the first time I have ever told anyone outside of my best girlfriend and partner.
TLDR; My mom herself was abused by her dad from a young age (he died in a house fire that someone in her backwater community set, I guess he touched the wrong kid) then raped twice by the same man on separate occasions, they didn't put him away until his wife came home one day to find their kids tied to their bed and being sodomized and had some shitty boyfriends in my childhood. I feel like those all contributed to her mental illness. Does your parent have any traumatic events that you think added to their mental state? I feel like sexual trauma and other childhood trauma is sometimes the hardest to get around or over, really.