What is it that bothers you the most about it, that you think you could've been wrong in your choice? It's common to go through stages in early adulthood where you're deciding through experiences in how you'll define yourself through your ethnicity. Being Native American, I can only imagine how hard this must be since not many cultures share that view; so you're left with will you try to disregard that part of your culture and assimilate to the main one to make dating easier? Or will you stay strong in your beliefs and hold out for a woman who will respect your culture and try to adjust? I personally feel she should've bent more towards your culture because Native culture needs to be maintained to be carried on, but she could've not had it in her to be able to do that. It doesn't mean she didn't love you enough, but was lacking understanding, experiences, and the comprehension of just how important it is for Native culture to be preserved through the people, otherwise it'll disappear. It hurt her that you weren't adjusting to her ways of understanding the significance of her parents in her life, and it's possible she saw it as not trying.

But with all this said, both of you weren't wrong or right. The mixture simply didn't go well enough together to provide growth for you both, while adjusting to what defines both of you- and that's incredibly ok! Of course, the pain could be trying to tell you you fucked up, you DID NOT. It's ok to be the person you want to be, it's ok to want to pursue your traditions, and it's definitely ok that you found it hard to speak to her parents, there's nothing wrong with you, I promise.

Does your therapist have any credentials in culture or sociology? Therapists aren't a one size fits all deal, they all have their own personalities and beliefs. I think a therapist with background in cultural study would benefit you the most in helping you move on, because they'll be able to comprehend a tiny bit better and be able to observe the situation from a more assisting perspective I believe.

If it makes any difference, I'm half Native American but was raised by the white side of my family. I've took it upon myself in my college years to learn more about my Native ancestors and I have a good idea as to how important keeping the culture alive is, as well as how cultural genocide is being largely ignored institutionally. This negligence in our public education system perpetuates the continuation of the original goal (to wipe out Natives and their cultures), but it's not acknowledged because the general public literally don't know... I can't imagine who hard it must be. I sincerely can't and will never pretend I can. But I hope I've given you good stuff to think about that will bring you a bit of peace in this moment. Doka!