Who/what's causing the panic? Just don't call her anymore and if she calls you, don't talk to her. Do other things in your life and "move on" and eventually you won't think of her as much, living life; work, school, other relationships, doing chores, etc. will replace the direct nature of the feelings, mute them to part of your memory as if you had moved or changed jobs, etc. Do you think about your third grade teacher when your in fifth grade? Same concept.