Ryan,
I’m sorry for your worries, I know how distressing it can be to have anxiety. Its sounds to me like you are far more invested than she is in the intimacy. I hesitated to respond, because it sounded like you wanted help in figuring out a way to keep her, but that doesn’t seem to be what she wants.
Sometimes we just have to accept that a romance is like a flower blooming, and it is beautiful while its open, but will fade in time. She sounds like she’s been clear with you, and yet you don’t want to hear what she is saying, don’t want to accept her moving on.
Consider getting out and following some of your interests. There are usually many groups on campuses, and perhaps you would do well to pursue some other sources of happiness. Namaste.
With warmth,
Matt