Maybe your T's use of the word tension is not meant to be a negative thing. She might have merely been trying to tell you that she was sensing for fear. Maybe by acknowledging it she was trying help you realize that she is safe to talk to.

Recently my T and I had a good exchange about silence. We had very different interpretations of it. When I would encounter silence during the session I would automatically interpret it as ... I was getting the silent treatment from my T because I had disappointed her or said something not acceptable. My T explained that she was being silent because she felt like she was interrupting me all the time. She said from her perspective I had a lot of difficulty gathering my thoughts and attempting to express them. She thought I needed her silence to allow me a chance to express myself without her interrupting.

The point here is my T was trying to acknowledge that I was struggling and give me the support and space I need. At the same time, I interpreted this as getting the silent treatment.