I get angry towards my brothers or sometimes towards my sister or even on cousins for their behaviour with me. When they don't talk with me or when they don't care of my point of view or call me "baby" as I am the youngest child in the family (but my age is 30 now and I have one kid too). I get so much angry that I pray bad for them. This is also not good for me. How to handle anger towards siblings?
Actually that happens to me too, and happens in many many families as well.
You just have to have faith in yourself that people all around us try to insult us, ridicule us, make fun of us in many ways, but you should just remember that you are better than them that you don't do this to others.
Just take example of our Prophet Muhammad. A woman used to put garbage on him, but he kept silent. People of taif used to through stones at him, but he kept quiet. His enemies used to mock at him, insult him and make fun of him, but he kept quiet and kept patient. But from where did our beloved prophet Muhammad got this level of patience? That is because he kept praying to Allah that may Allah grant him patient to bear all of the hardships.
So keep praying to Allah that may Allah give you strength to not get angry over whatever others do to you.
And another thing is that, it doesn't matter what people think of you. People never give importance to us ever in a way that we want. JUST have attach your expectations from your Creator, Allah. And always keep thinking that you have to keep ALLAH happy. If He is happy, Everyone will be happy with you. If He is angry, then your whole life will become a mess.