I have been working on something very similar in my work for the last couple of months.
I FINALLY broke the pattern of getting defensive in a challenging relationship a couple of weeks ago. It felt amazing.
I was aware I was defensive for a long time. Finally about six weeks ago I realized in a therapy session that the "feeling" of being defensive for me is less about me "knowing" and "being" in my body and it is more about trying to make myself liked, respected and understood. That usually happens though with people who because of addiction or their own "stuff" are not capable of meeting me there. In other words it does not matter what I say or do they won't "get it."
I get that way in this one work relationship. I was having a 1:1 meeting with this woman who can trigger me. I triggered and I just said "okay," and ended the discussion. It was NOT me backing down, it was NOT backpedeling, it was acknowledging that I had the right to my own opinion and I needed to honor that and "discussing," it was not going to make a difference for her at all.
This whole recovery journey has been about honoring and trusting me.....regardless of what feedback from outside sources. I am starting to realize my defensiveness is a product of my co-dependent behaviors and lack of relationship with myself.
I have also found in the last number of weeks about who I feel this with often and who I don't......and that tells me a lot about my relationships in a way I did not have access to before.
I can't wait to hear other replies.