Oh that's hectic @creative_writer and really hammers home what you've been saying about how these beliefs have formed for you. Despite what the internet says, in my opinion we are all responsible for our own triggers. It's legit impossible to participate in the world and not be exposed to potential triggers. We can and absolutely should reduce potential triggers where possible (like our guidelines on here) but you accidentally triggering your mother is NOT your fault. It's not hers either - it's simply two wounded humans bumping into each other, knocking the wounded parts and having to nurse the pain for a bit.
Also, like @tyme said, this is why I don't talk to my parents about my mental health. One time, my mother wanted to know why I was in therapy, so I started talking a bit about my anxiety, my self-doubt, my insecurity. Her response? "Oh no, does that mean I wasn't a good mother?" Yikes. Now suddenly it's no longer about my pain and my attempts to heal from it, and all about me putting my emotions on hold so I could reassure her. So... I feel you. It hurts to get shut down, and hurts worse to get blamed for upsetting someone, despite the fact that in that moment you couldn't have known - you just needed them to listen and hold space for you.
Humans are experiential learners. The best way to teach the mind and body that it is safe to be emotional is to have repeated experiences of the thing that once made you feel unsafe (being emotionally vulnerable) being responded to very differently from how your mother has responded in the past. Having someone respond without judgement or attempts to fix things, and without exploding at us or guilt tripping us, does wonders for rewiring our brains. Hence, therapy. Therapy can actually help us relearn what it feels like to be safe in a close relationship. It's a very unique kind of relationship, sure, but it still works to teach our primordial monkey brains that we don't always have to tiptoe around on eggshells, bottling up anything and everything until it explodes out of us. Whilst it may always be that way with your parents, building that ability to allow ourselves to feel safe to be vulnerable makes it that much easier to break the cycles we inherited from our parents - especially as we move into new relationships. So yeah! Therapy! Knew I studied it for a reason 😉