It's always important to keep some emotional distance between you and your therapist, and it's never a good idea to treat them as a friend, in the most common sense.

That said, spying on someone as a matter of course is definitely unethical, and you're better off without her. The way she handled it says loads more about her narcissistic tendencies than it does about any error with regard to your holding things back. Therapy is meant to be a process whereby you get a sounding board periodically to process the things you think of in your own time. It's not meant to be a confessional booth where you confess all your sins to the priest and gain absolute freedom from your troubles.

You're better off without her. Definitely look for a support group. You'll be able to give and receive better under that model, I think.