Does she not like me anymore? What is going on with her?

My girlfriend seems to never wanna talk to me face to face or hang out. Its been this way since we started dating and she always said she was just really shy. We talk through email and thats the only time she wants to say how she feels, I love her personality when we talk through email. We've made a lot of plans to hang out but it never really happens, but today we were gonna go to the mall, she bailed because she was apparently out of town and wouldnt be back for awhile. My cousin called her, and she answered thinking my cousin was me, she groaned and said oh my gosh, she lied to me! I hate liars. Is she over me? How should I react? WHAT DO I DO?