Have you thought how NC felt?

From the stories I heard, majority men, Chinese or American, have difficulties to distinguish between flirting and being friendly. NC was just being nice. Though she liked talking to you, I am 99% sure that she had no other thoughts for you. Then, you wrote her an email and of course she would feel uncomfortable. After telling you to stop this kind of conversation, you wrote another email on this...

Like other people said, graduating ASAP is what you should do. You made mistake. Even it is not your intention, you made another person feel offended. You pay the price. It has nothing to do with being a Chinese.