I don't think it's appropriate to tell a survivor of childhood trauma that they should trust someone. Anyone. Why would people who needed protection from their early caregivers trust anyone else? As others have said this is delicate work and I'm not sure a T who is very cbt is cut out for it.

These are questions that need to be asked much more carefully. You don't ask trauma survivors why nobody helped them.

I don't think you have failed, sounds like you are doing great. But I can't help thinking you need a T who will honour your right to distrust them.