I had a friend who was constantly anxious, enraged, hurt, upset - and her therapist asked her to check internally if what she was thinking as a result of this was true. Looking at your first sentence "I'm scared" is true, but the second part that a therapist will think about you like your family does is unreasonable don't you think. You hire a therapist to be understanding and help you, they do not live with you 24/7, they did not give birth to you, they are a space separate from you and family . Lots of people omit telling things when they are nervous. It's sounds like it is important for you to come clean about this because it's a toxic issue for you... and because trusting someone means testing being open with them. Do what you need to do and ask how she feels about it.