If the therapist is not the target of your anger, then someone else is. It may be one person or a group of people, but whoever this is, they are clearly someone you are afraid to express anger towards because that might result in some bad consequences for you or you might be unable to express anger towards them for some other reason. So, you are displacing your anger on the therapist then. Displacement of anger is a classic psychic defense that allows the person not to address the source of their anger directly while still releasing the tension the anger creates on someone else. Displacement is a major cause of bullying and other abusive behaviors. I am not saying you are a bully. I am just explaining why people use displacement.