Conversation so far:
How does season 7 of Buffy the Vampire Slayer start for Willow Rosenberg?
The seventh season starts with Willow Rosenberg in England, unnerved by her power, studying with a coven near Giles' home to harness it.

Question: Why is she unnerved by her power?
Self-contained rewrite: Why is Willow Rosenberg unnerved by her power?