You are unique. Don't you ever try to ape that girl in the magazine or the most popular one in school or even the prettiest star on television. They are living a story of their own, with its own path, journey and destination. If you change to be like them, who is going to live your story? Who will reach your destination? I know you must be having a hard time getting this but some day it will be crystal clear.
As women, we are constantly policing other women. If she puts on bold red lipstick, she's looking for attention. If she's wearing a sleeveless dress with unshaven arms, she's trying to make an unsightly feminist statement. If she doesn't smile often, she's too uptight. If she makes a good presentation, she's trying to make other women look dumb. All these are instances are examples of internalised misogyny which makes women despise one another for irrational reasons.