Dear Aiza,
You need to be more polite towards your brother. Remember your brother is younger than you. He needs to know that you love him and care for him. As soon as he realizes that you are loving and friendly towards him, he will surely change his attitude. There are different ways of showing your love. You can help him in doing his homework. You can sometime pack his bag. You can buy him some gifts of his interest. Trust me it will really work.