its okay to feel scared! even if you dont get a response you want, im sure it would be better knowing the truth
she could feel a little odd talking to you a lot so suddenly considering you havent spoken in a while
but if she really is trying to avoid you then im not really sure how to help you. well see how this plays out.
you can confront her about it if youd like to
maybe shes just getting annoyed with you trying to call everyday, ask her about it
or theres a possibility that she really cant call