Struggling to share what's coming up with therapist

Just started EMDR with my therapist who I've been seeing for 4 years and trust implicitly. I've always struggled to share deeply, either I dissociate and go numb when touching on deep topics or I intellectualise with no feeling in the room. I have got better at actually speaking up (rather than freezing!) once we reach a certain place. Feeling however is still tricky.

Today was our first session. I felt super panicky knowing we were hitting the hard stuff. She asked for a memory relating to the issues I experience and felt to embarrassed to give her the big T event from my childhood so gave something from school. Predictably big T trauma event flooded the memories popping up but sharing what I was feeling/remembering was just too tough. I sobbed with pain I've refused to feel for most of my life and at moments it felt totally overwhelming. I couldn't share most of what was surfacing. I felt SO embarrassed, silenced and choked. For a fair while I just kept saying "more stuff" every time she'd ask.

I wondered how much others are sharing when their memories are surfacin? She knows all these traumas in detail already so it's frustrating and sad to not be able to share. I'm a chronic over sharer yet here I have no voice.

Thoughts would be really appreciated ❤️