الجواب:
بسم الله الرحمن الرحيم Allah create human (indeed we have fashioned mankind according to the best organizational plan) the god said in the holy Qur'an . It happened some times Allah test the people by some disease and some illnesses. You said my deer sister in your question that you want to make plastic surgery to change your breast . I think this is not halal because there is no need for that , and it is not make big different and it may be changing Allah creating and Allah knows best.