Good for you, I know that was really hard, but really, very liberating!!!
Maybe now she will realize how she has bullied you. Or maybe that is just the way she is, but you had a right to stand up for yourself. Sometimes people are just nasty. Or treat others badly because they are jealous... (or maybe she just needs some chocolate?)
Do NOT feel guilty about what you said to her... you did it in a diplomatic way, and have nothing to feel guilty about. If she tries to guilt trip you, then she really is a bully.