Relationship SO highly dysregulated - Why break up after getting diagnosed?

My SO finally got a proper diagnose after long time supporting. She pushed me far far away, with first that here will be absolute no contact at all ever. Later she said if there will be contact only after therapy. She is really afraid who she will be after. I really think she hit rock bottom after i told her living together with children is not safe, and that she breaks everything around her. She moved 100 miles away to stay for long time with childhood girlfriend.

Two weeks after the breakup / push. I still recieved a very kind birthday card. And i am still allowed to make time for her own child. Its a bit confusing. No contact at all ever, but still allowed to spend time with her kid. Same for the birthday card. Most of the stories are about complete all ties cut.

She is at the moment highly dysregulated. A lot of stress from a ton of things she did. No real living space. finance problems, no job, problems with her ex about their child. And on top of that cptsd diagnose. She fought long against it. Really survived before i met her. And spiraled really downwards while we where together. i really found her beautifull on all sides. She was absolute not ready for that kind of words and attention. Spend a lot of time in patience, and kept very calm friendly and loving all the time.

I give her all the space she needs, as long she wants. Told her loving is also letting go. No fights or bad words etc etc.

In the meanwhile i spent a lot of time reading and understanding about ptsd. For example understand about the 3 sort of connections. Strangers, friends and people they love. Me and her sister both are pushed away.

My main question is, why break-up / push away after she got the diagnose. I spend long time to convince her that we also have to work as couple. But that part is refused/ignored from day one. I understand self sabotage is also part in this one. I told her that she can always contact me if she really wants to, if the need is there during therapy. I have also the feeling she protects me from doing more pain at the moment.

I am calm, miss her but not grieving anymore. Accepting the situation, and have slight hope for a future. It gives me time to prepare if we get back together. Just want some thoughs and insights about this.