how do i stop being emotional

i 17f have always been emotional, 90% of my memories as a kid are me crying and everyone telling me to stop overreacting, and i am overreacting because when it gets solved or when time passes i feel like it was stupid but at that moment it felt like the whole world depends on it. i want to stop being like this, recently my mom and siblings told me they avoid talking to me because they don't want me to cry or overreact. i think it has been getting worse because I'm a high-school senior this year , i don't know what's it like anywhere else but where i live it's alot of pressure. so how do i stop being this way