This is the same girl, isn't it? Haven't we been through this before? There are a few girls (and guys!) who are worth pursuing, there are a lot who aren't. She likes the attention. Stop pursuing her. If the two of you are meant to be together, if she truly wants to be with you, she'll make an effort to let you know how she feels.
But you are young, and maybe it's a good thing for you to experience the hassle of unrequited lust. It's an important lesson in life and now is the time to be learning these lessons.