LorienLlewellyn
You can't blame her for having other friends. Sometimes people click with someone they haven't known very long. People also might not click with someone they have known for years. So length of time isn't necessarily a determining factor when it comes to who people want to spend their time with.
It's a shame, but friends do come and go. That's especially true when you are young and are growing and changing a lot. If she doesn't seem like she wants to be friends anymore and even says you scare her, it might be best to just let go.
Seconded. She doesn't sound like she has much of an interest in the friendship anymore, as much as I don't want to say it, and if she's hurting you then it might be better to walk away and leave the ball in her court (her renewing the friendship in the future if that's what she wants to try).