What shall I do I’m so upset?

I know its annoying but it means she looks up to you big time and lacks the confidence to make her own choices.

I had a friend like this, eventually, she got her own personality and became a lot more enjoyable as a friend. don't cut people off for dumb reasons. Don't listen to these dumb comments labelling her as a narcissist or a bad person

The less information you provide, the less she can use to imitate  you. But it really is no big deal, its a form of admiration, it will pass eventually, turn your attention to more important things.

Did you know that when someone imitates you it's considered the highest form of flattery.

She is a narcissist distance your self from her. They do that to steal your essence because they have none of their own.

I would turn it into a game. Tell her you are going to jump off a cliff.

It seems like she is obsessed with you. You should politely ask her to stop the obsessive behavior...