What about izzy as a nickname?

Hello!! My name is Isabella and i have been called Isabella all my life! I am twelve years old and in year seven and I really really want to be called Izzy so badly! My parents absolutely hate the nickname and call it common and they refuse to call me it:(. Especially my mum. My mum lived in Brazil and calls me the most stupid annoying foreign nicknames in front of my friends!! It is so annoying and I want to be called Izzy so badly what should I do?