How do I change my entire look to look different from somebody that looks exactly like me?

I have a twin and I hate looking just like her. She did something bad to somebody and that guy hates her. The guy thinks I'm my twin and he treats me so bad and spread rumors about my twin and It makes me look bad. My twin has the same body, height, face (our eyes look a alike) and Same exact hair style. Pin straight hair and I hate dying my hair a different color just so I could look different.