'How does the shift take place?' Listener question

I’ve been pondering the experience you often described of sitting with a feeling and inquiring into what arises as a healing space of awareness, where a shift happens. 

And while I’m sometimes aware that there is no me to do it or anything, I wonder what actually happens when a shift occurs and how whatever happens takes place? When I think there is a me doer, I wonder how best to inquire into it, to see through it, make it transparent?

This may be the result of way overthinking it, and if so it wouldn’t be the first time.

An example might show my pondering:

I talk on the phone with my darling, beloved sister. She shares with me what’s been happening in her life and I note an edge in her voice when she tells me of something particularly good that has happened to her. I hear this “edge” as bragging, a subtle putdown, and feel annoyed and jealous. I’m aware that I’m feeling this and then add on top of this a level of self-recrimination and guilt, as annoyance and jealousy aren’t “good” emotions. I love my sister and feel I should be happy for her, period.

So I feel all of this and sit with it. I feel diminished and I feel icky. And then I inquire about what’s going on. I see old childhood rivalries and competition for parental love and attention. I see where, sometimes when I talk with her, I am annoying and bragging. I own it.  I allow as we’re both human we’re entitled to express human emotions. I see that our reactions come from our body/mind systems of how to be in the world. I allow as what I heard in her voice was my own projection. I’ve taken an endless deep dive into my psychology. 

This may be well and good, but it feels like drowning in concepts and beliefs. Every “rational” explanation feels like another card in a house of cards that is built on vapor, going nowhere. How is this healing?

I wonder who is doing this diving and feeling and inquiring? Is this the body/mind busy defending its existence? Is this a process, a practice, for 

healing that, like Bryon Katie’s The Work, becomes steps to be followed when a constriction is felt? Or is this inquiry description only of what happens when feelings are felt with inquiry, not a prescription? 

What makes the shift, the flip from personal to impersonal? Sitting with the feelings and inquiring into them can feel like endless, pointless suffering. What is it in feeling the feelings, asking in curiosity about them, that shifts to the allowing of it, the accepting it, the witnessing it?