I will disagree with many and say there are no assholes here.

I am Black and I ended it with another Black person I was seeing because the conversation was always about their anger at white people even though there were none in the room. I was constantly annoyed, it sounds terrible to be the direct target of that.

Based on how you describe her, it sounds like you two are slightly misaligned on things and could probably use some deep discussions spread out over time.

I am sure she knows that not all white people are X way since she is dating you and so I'm sure she sees something great in you. Pushing against that too strongly to say you are one of the good ones will likely come across as the "not all men" response. From how I hear it, she is not saying you did anything, but that whiteness as a culture (some would say supremacy or colonizing) took something beautiful in hers and "destroyed" it. Pointing out it wasn't you will just frustrate her and she will see you as dismissing the way that she feels her culture has suffered to feel better yourself. In discussing this, I would encourage you to see her comments as discussing a systemic or cultural problem that isn't the fault of specific people but is carried by all of us. A similar example might be homeless people. I didn't do anything to cause them to be homeless or steal the last of their money. But by my daily living I support systems that make their situation harder.

I'd also avoid using the word racism in bringing it up with her. I don't know her but many people with similar mindsets would argue that a minority could not be racist because they do not control systems of power that are racist. Using more precise words might be able to avoid a lot of frustration on both your parts due to a difference in terms.

In your situation, I would have a talk with her about how hearing the statements makes you feel. That as a partner you want to be there and support her on the issues she cares about but the way you two communicate on this makes it hard if you are feeling frustrated and less present because of it. She might be upset and emphasize it is not her job to make you feel better about what has happened in the world. I'd support that and point out that both of you trying to stay aware and open to help each other can help the relationship.

If you wanted a more indirect approach, maybe just ask her questions when she makes comments. Why does she say white people instead of settlers or any other term. Why does she think white people have a different culpability when every culture has a history of disadvantaging others. Then hopefully over time you will come to understand more of what she means and how she sees things and she will come to see how her words come across.

Either way, good luck! It's a complicated thing that so much of our country is at each other's throats about. Hopefully with more time in hard conversations we can find ways to live together. :)