Insecure about my boobs

I'm 16, 5'2 and I weigh 8stone(think that 110lbs) - I have size 32C boobs and I'm really insecure everyone around me has D's,DD's and E's. Even my younger sister has bigger boobs than me!!(shes 13). I'm considering getting a boob job when I have enough money but I don't like the thought of getting it replaced every two years. Even my boyfriend said that any boy would want me to have bigger boobs😪I don't know what to do or how to make them bigger naturally, has anyone got any ideas?