Her aunt should not have done that, but she has a history of behaving like this. 

We all have things in our lives that we want to scream and stomp about, but we don’t because it’s frightening and hurtful to the people around us. Imagine if every time you did something that made someone else feel bad, they started yelling at you and telling you how much they hate you. If you grew up in a family that was like this, I’m sorry that this was your reality. It is not one that anyone can live with and come out unscathed. 

While it’s important to be honest about how you’re feeling, nothing gets solved by throwing a tantrum. You always want to be the bigger person when someone is wronging you, and you will never be the bigger person by yelling, «I hate you» to your cousin for being passive aggressive towards you at the family reunion. Just because you have big feelings doesn’t mean that you have the liberty to express them in the most uncharitable manner. It doesn’t matter if you have mental health issues or if it’s your birthday. You need to learn how to regulate your emotions sometime.