The girl who likes me is stalking me!? What to do?!?

There's a new transferee girl in our class named Daphne, we're classmates.. juniors to be exact. She's beautiful.. I admit. I'll Take this short we've introduce ourselves to each other, talked, laughed. Shared good moments.. I even start liking her. But one day i was walking alone to go home i noticed tht someone's following me.. But i just ignored it. I reached home and someone knocked at my door a few minutes and opened it but no one's there but there's a letter saying "i like you so much! i'm obsessed about you kean" i don't even know who sent me that letter since it has no name. So the next few days i heard rumors that daphne just enrolled here in our school cause of me and he's been checking me out ever since. She knows my parents name, my sisters name and age. & a lot more things! She even has my baby pictures and family photos. & found out that she's the one calling me at the house everyday @ 3AM. I am freaked out, i suddenly didn't like her instead it scared me. & now she admitted the truth.. It's all true and i don't even know what to say. Help me!