Do Not Take Things Personally
It is not all about you. When you are defensive by nature, this essentially means you are not open to new information. Defensiveness is a form of hypersensitivity, which can come when you think someone is insulting you when they, in reality, are not. All you have to do is be open to new information. It is not that threatening. It is just information for you to think about. Stick to the facts not the emotions. Try and be objective not reactive.