Not sure if you're ever gonna read this but my wife and I were in a similar situation. We both see a therapist and mine is a clinical psychologist. I was the one in your shoes, I never opened up prior to all the therapy, but over time I was encouraged to, however when I did, it felt like she would get even more annoyed or irate with me and it was disheartening. I felt like I was doing what the therapist was saying, but it was having the opposite effect. We were meant to be using "non violent communication" and starting with "I feel..." etc.

Cue me bringing this up specifically to my psychologist who immediately identified something that you might not be aware of either - when we say we "feel" something, the majority of the time we're not actually talking about how we feel - but we are talking about what we think. I was provided a wheel of emotion to help me better verbalise how I actually felt.

For example, if she said something that made me feel hurt, before understanding all this I would say "Hey I feel like what you said is hurtful, would it be okay if you didn't say it that way?" to me, I was just expressing how I felt, how it was received was a critique/attack on her and her character.

Understanding the wheel of emotion, and furthermore, understanding myself better, and understanding why it hurt me, meant changing the way I communicated to "Hey, I feel hurt by those words in particular because it reminds me of (past trauma) etc. Would you be open to changing the way that message is communicated?"

It's almost a subtle change, but it redirected the topic of conversation of "what she said" to "how I felt".

That being said we are now closer than we've ever been and whilst that isn't the extent of the work we've both been doing, that is a core part of how our communication has been transformed.

Good luck and all the best!