:: shivers!!! ::
Some of your description of your mom's treatment of you connects with some of my story. ACK! SCARY! But, it's OK for me to say that, and keep reading and responding. We're never "the only ones", you know?
It sounds like, your colleague had garden variety fears and self-doubts, so it's understandable that she was able to quickly accept and assume the emotional security needed to be a mom. The level of experience might've been way less intense for her, you know? From what you've written, what you experienced wasn't just a normal level intensity of friction between a mom and daughter. It's clear your experience was intense, and lord knows, it wasn't healthy for a child. What you experienced was something "completely different"... and I'm gonna go out on a limb & say that this experience probably makes you a better mom, than you think.
I have one suggestion that might help with your immediate "present moment" needs, while not forcing yourself to just "get over" the feelings, memories and experiences that are coming up for you. Schedule a specific time each day to write some of this out. Doesn't matter if you journal or use "Kay's Story". Whatever feels right for you. A time that's quiet, undisturbed and just for you. (hard to do with kids... but they'll get used to it, too!) You also need to limit the time, to whatever is manageable and allows you to "return to" and be fully engaged with the rest of your life. The idea is to keep the two time frames separate - past and present - in your writing. When there is a great need to "tell your story"... it will unconsciously show up in your work on topics that may seem completely unrelated... unless you dedicate a sacred space/time to honoring that past, all by itself. This is an appointment you NEED to keep with yourself and if something comes up that is "more important", you still have to make up that time and give the part of yourself that needs to "get all this out" and deal with it the way you want & need to... that time and space. That's what I mean about making a sacred place for this. It's honoring what you've lived, who you are, what you need... and it's also a way to "process", i.e., come to terms with what your past was. This kind of journey enriches life and experience and helps you grow and blossom... even though parts of it can be emotionally difficult, stressful, and maybe in some places, horrifying.
We've studied and in some degree, come to terms with, our own dark places and experiences and "things done to us". And, in some degree again, been able to leave it in the past and "get over it". You can too. [disclaimer: we still have bad days and times, too - that's just life] You are not a "hopeless case" and I'm gonna guess again... and say there's nothing really "wrong" with you that can't be "put right" with the process of telling your story, your way and finding out you're not "the only one".