get meditative about it.
What is that person trying to teach you (and I dont mean finance)? Perhaps she is meant to train you on being more relaxed when confronted by a condescending douche. So learn to be relaxed, its better for both of you. Maybe you can even figure out how to train her on being a nicer person. By being nice whatever she says or by sying things like "You are right, I would feel more motivated if you say it like this...."