Out, safe, but struggling with boundaries & guilt

That guilt you described sounds a lot like 'toxic shame' -and I think it is remarkable that you already made the connection to how your own mother treated and treats you by yourself! That is not an easy thing to do and I believe you can give yourself a lot of credit for doing that, and for reaching out to others.

Now first of all I am a huge 'fan' of finding a good, professional mental health care provider. Especially if you are dealing with possible complex childhood trauma like your situation could very well be. Your mother could be on the narcissistic personality disorder spectrum. I say COULD because nobody but a licensed therapist is allowed to make such claims of course.

A few books that I found useful if you feel a lot of this toxic shame and lack of self-compassion stems from your mother are:

"Will I ever be good enough" by Dr. Karyl McBride.
"Toxic Parents" by Susan Forward
The Wizard of OZ and other narcissists" by Eleanor Payson

Again, I have to stress nothing compares to having a professional counselor by your side, who can guide you on your healing journey towards the resources that suit you individual situation the best.....

I find what you described actually also very interesting for ANY victim of abuse, past or present- because very often we compulsively repeat the dynamics of our relationships with our own parents and fall for abusive partners-- because it is familiar, it is what we know. It is also a distorted view on what love and intimate relationships are like, leaving the victim left wondering what is wrong with her/him and why they always feel like this.

NONE of this was ever or is your fault. Period. None of it!!
You had the right and needs as a child and young adult to have compassionate role models- your parents. YOU ended up taking care of your mother's own emotional unmet needs and she caused a role reversal by that. No child should experience withdrawal of love and attention from their primary caregivers.
It makes you scared and it makes you feel like you caused it, because children deify their parents and think of them as perfect and god-like when growing up. When something bad happens, of course every child assumes false responsibility for it....if mommy is acting bad towards me, it is only because I must BE bad...

When in reality- mommy is probably acting bad towards me because she is not a safe caregiver and NONE of this is caused by the child, ever.

I hope you find a wonderful counselor - google 'warning signs of a bad counselor' first before you look up one in your area. There are a few websites that allow patients to rank their counselor too, maybe there is a ranking for one in your area, or a good recommendation from a close friend even. Give yourself permission to be in the driver's seat of your healing, meaning change counselors if the first (or second) do not feel right after a session or two. There are extensive lists you can easily find via a google search that explain your rights as a patient, but also how you know how it should FEEL after the first one or two sessions already.

Hope that helped!