Wow, I’m so sorry you’ve been through all of that.
I understand there are two sides to every story though so it is difficult to say what is “right” and what is “wrong”.

The main thing I think after reading your post is that you both need to work on yourselves before entering into a relationship.
I know you said you have a therapist and she has only just started seeing a psychologist.

From what you’ve said, I think you need to learn about what is good for you and what is abuse, it’s not surprising that you doubt or compare yourself to others when you’re in a relationship of the kind you have described. And she needs to learn to open up and stop resorting to anger. But this is only from what you’ve said. It’s difficult to know as we only have one side of the story.

Saying that, I agree with @Yaowen I wouldn’t be in a relationship with that much drama. I don’t agree that there are things you “shouldn’t” talk about otherwise an argument will be started. I think relationships require communication and honesty and it doesn’t sound you have that.

I understand she sounds like she has had a traumatic past. But I think it’s unacceptable to treat someone badly because of that.

Now it’s time for you to think. What are you going to do? Are you going to work on yourself? Are you going to go back to a relationship like that?
Are you going to take some time to think?

You don’t have to answer those questions, it’s just for you to think.

Regardless I’m so sorry you’re in this situation. It sounds like it’s been somewhat abusive and that’s not ok.
Sending hugs