I relate to so much of this. I also trust my therapist (and much more than others, because I can also be this younger more vulnerable self, vs just bitch about work like I used to with other therapists). But after a few years I still often feel disconnection because I'm trapped on the other side in my own little universe.
She asked me yesterday what my younger self needs to feel safe. I wish I knew.
For me this has taken a lot of right brain sort of freedom. I'm lucky my therapist has a shelf full of toys, gadgets, stuffed animals. I asked if I could just go look at one. She offered to get it for me, but I wanted to get it myself, which took the whole hour, dragging myself on the floor and stopping to cry or breathe into a tissue like a little oxygen mask. She moved with me and we both held onto a piece of fabric...so 'connected' and not all alone. I still feel I'm in a bubble, but more often that she can at least see me in there, or is with me, even if the connection is difficult. Lots of other little bits more related to somatic/body focus therapy I'm doing. But connection is the reoccurring theme.
As for the safety, I got a little stuffed animal after an hour (just accessing comfort or connection is PAINFUL and slow). After a couple weeks I moved up to pretty normal sized teddy bear. My logical, successful adult would have none of this. But it felt safe and appropriate within therapy. And I learned that holding a stuffed animal does comfort me and also allow me to stay a little more connected and present. Sometimes I color or scribble, other times just curl up in a ball. For me the body and movement approach has helped break through my barrier because I get so mute anyway. But I can have some feelings and even cry a little without needing to have language for everything. That's not saying switch therapies...not sure what you are doing. But experiment with whatever gives you a sort of warm or comfy feeling, like you are a little more connected within yourself. That might just be a certain postures, a toy or object, or a sense thing. Sound is very helpful for me (I also have brought tuning forks to therapy...help me ground). This is all stuff that connects to that "inner child" (I don't use this term) but also help me regulate and stay connected in the present. Tactile, sensory things usually....
One last thought...I've done a mirroring game with my therapist that felt helpful. We faced each other and I copied her gestures for a while, then she copied mine...just moving my hands or arms in some way, whatever. I didn't have to really make eye contact, but I had to stay connected. And this mirroring or two-way connection was likely largely missing from my early life. It's like a silent conversation, and kind of fun.
That all being said, I feel like what I'm still working on is feeling connected within myself, and that has improved. It has taken a few years though. So even if you feel a little more connected within or to yourself, that's big progress and connection to others supposedly develops along with or a little behind this. But it's like I'm learning how deep this disconnection goes because it is very hard to move around....like you, I notice this in relation to a good therapist (the others I'd say I didn't even notice the deep disconnection because I was a confident surface self with them, which was therapeutically meaningless). If it's really easy for me to make eye contact, chances are I am somewhat disconnected within myself. The challenge seems to be staying connected to myself and my therapist simultaneously. For most of my life, myself or the other significant person had to become somewhat unreal. So it's really hard to rework that deep pattern so that we are both real, or connected.
