Defend yourself. If she tells you that "I looked great yesterday" find a polite response to that. If you don't defend yourself she will continue abusing you, and you will keep feeling bad about yourself. If she doesn't change, then you need to think about your relationship altogether. But I would try the first approach as you said you have low self-esteem. An unfortunate fact is that people with low self-esteem are viewed weak, and thus will be taken advantage of. So, I suggest to start with your self-esteem.