This is an excellent question - I know you are asking from a place of pain (I hear that in your writing, it comes through loud and clear), but this is a question that I wish every person in a relationship should ask.
When there are fundamental differences, such as the ones you describe, most often they are overlooked early in a relationship. When you two first got together, you probably were having a good time, she was on her best behavior, you were delighted to be in a relationship... everything was nice. But over time, a partner's rigidity and fundamental attitudes belied a number of underlying issues that she is harboring, and absolutely will not change unless something big knocks her out of her trajectory - in other words, there was perhaps very little you could do because she was acting on traumas that happened to her long, long before the two of you met.
So here's the deal: In my opinion, given the circumstances you laid out, you did absolutely the right thing to cut it off now. Imagine if you waited four or five years, had a kiddo or two with her, and one day (finally?) woke up and realized that you were abjectly miserable with her. Then what? Now there are kids to consider, and you would feel trapped. So better to get out now - yes she is furious and yes you are in pain, but this will fade over time with no collateral damage of children hurting as well.
Listen man, breaking up hurts - you are dealing with it appropriately, and she is dealing with it by turning on you and lashing out. Who is more emotionally healthy in that scenario??? Fall back, lick your wounds, and when you feel whole again, go out and test the dating pool one more time. I think you should learn from this experience so you don't step into the bear trap again - if you snag a nice gal next time, you will wonder why you waited three years with the current one!
Best of luck - grieve the loss and move on. If you are satisfied with the response, please hit "accept." That is the only way I can receive credit for my answer. Thanks-