You did what you have to do, sometimes you have to let people know that, you being an introvert doesn't mean you re a fool, you just decided not to let lion inside of you to come out, and once in a while is good to let the lion out, so people can respect you and stop taking you for granted. I'm glad you let your own out and later deal with it by sorting things out with her. Trust me, she's wouldn't dare do that for you next time