Post Break up communication

Attachment styles in themselves don't explain or excuse really bad behavior, and what you've described with her goes beyond. Based on what you've said, I'd guess she's actually FA but comorbid with other mental health problems (can't tell you which just from your post though). She certainly seems to lack empathy and object constancy.

Attachment styles help by revealing what issues and patterns you are dealing with within yourself, why, and give you a starting point to heal trauma and work through things (preferably with a professional) to get more secure and overcome existing fears and dysfunctional coping mechanisms and relationship skills. As far as it goes in describing another person, it can be really helpful to understand how your insecure attachment style interacted with someone else's to explain the dynamic that emerged, which gives you a lot more insight into why you might tolerate unacceptable and painful, toxic behaviors, more information about what you're looking for in a romantic relationship that might make you happy instead of drained, and a basis for outgrowing that dynamic and attraction to that type of situation in the future. It all takes a lot of introspection and work to do some deep down healing that goes beyond how your issues manifested in this one relationship, but rocky romantic relationships can hold up a mirror to your own issues and how to overcome them if you'll let them.

I'm truly sorry about the pain you've endured to get here, and going no contact and moving on is absolutely what's best for you. Her words are selfish and manipulative, and she's not looking out for your best interests at all. You need to look out for yourself and protect your own boundaries in a healthy way. Especially since she clearly has boundary issues, and lacks the capacity to treat others in a healthy emotional or respectful way. So do not let her steer the wheel, or she will continue to crash and burn your car. At her age, this is who she is and it's not going to change because she doesn't sound like she's questioning anything or wants to change. You coming here to ask and introspect after finding attachment theory means you are becoming aware of the bigger picture, and if you choose to have a growth mindset, outgrow the situation with her, and rebuild yourself, you will end up in a much better space in your life while she'll stay unsatisfied and on repeat (which is not your problem).

FWIW, I've been told something almost identical by an FA ex: he didn't feel how he thought he should. (I later realized how he thought he "should" feel about a romantic partner was not emotionally healthy, and was an outside ideal he was imposing on himself to define his feelings because he was too disconnected from himself to understand how he actually felt about pretty much anything.) He also didn't respect my boundaries and tried to instantly impose a friendship on us, and eventually going no contact for a long while when I felt unheard, steamrolled, and broken down by his continued outreach, in addition to being devastated by the breakup in the first place, was the BEST thing I could have done for myself. It was the first step towards recovery and rebuilding my self-esteem.