I also don't think there is any one size fits all answer to such a general question. Something from childhood... There can be a million different things and million different treatments/possible solutions. I think you need to be more specific to get more useful responses, or if you don't feel like doing that here, definitely within yourself and in your therapy.

I did not have significant traumas in childhood and my family was as loving and protective as it could be, I definitely received a lot of attention, often too much. The one thing from my childhood that always comes up when I ponder adverse experiences that had lasting effects was long-term peer bullying about my weight (I was overweight until age 10). And being overweight was mostly due to my mother's not knowing how to express her excessive desire for care in very constructive ways and in healthy doses, so she chronically overfed the whole family. The consequences were quite diverse, including an eating disorder, self esteem issues, perfectionism etc. My solution, as an adult, to all this: knowing that it was all in the far past and there is no way on Earth it could happen again now. Nothing from that past is current now and they haven't been for a long time. I talk about it sometimes with people, like now on this thread, when I feel it can be interesting in a context to highlight something with examples, but that's about it. I see no benefit in discussing it any more because it really has no relevance to my life now other than actually some benefits from having to endure those things, e.g. having an ability to "armor" myself quite easily, not being vulnerable to others' BS, insecurities and manipulation. So, some of that old stuff could be turned around quite effectively and I did not use any therapy for it, just my own research, trying to work on my lifestyle and choosing positive relationships. I also still like to keep an eye on my weight and don't feel comfortable gaining beyond a certain limit, so do not allow it. That keeps the problem non-existent because I do not let it manifest and bother my mind that, I know, is "primed" for it. So this is an example for an old issue and solution to it over time. Again, I find it most useful to tackle specific problems with tailored solutions, I don't believe anything generic works well in mental health. Or if it does, the result will likely be quite weak as well because the definition of the problem was also vague, to start with. Another old issue I had going back far into childhood was procrastination and poor discipline. It never even caused significant problems until my mid-30's, but then it started to be center-stage because I took on a bunch of responsibilities that were just not compatible with poor discipline. I could easily trace it back, where it came from in childhood and why, but that alone never solved it. Action did, to some extent, put I still struggle with it at times. I can talk about it forever but it will make zero difference if I don't do things differently as well.

But in terms of using therapy for benefit - I really don't believe that just going to an office however frequently, and doing nothing to follow up and implement changes in our lives, will provide any very effective relief. If someone only/mostly needs emotional support and a compassionate, understanding presence, maybe it is enough. But I think most mental health challenges do not remain there purely. Plus, it's possible therapy is not the answer at all. It didn't do much to me. This might sound as a judgment but I never truly understand why some people go to therapy for long years, even decades, when they feel it is not working and, in the end, they conclude it was useless. Maybe because it is not always easy to judge the usefulness of something in the moment, sometimes even for a long time, while the problems are still ongoing. Sometimes we also like to cling to hope alone. My last T said once said though that the biggest part of the therapy work occurs (or should) outside of the actual sessions, in the client's everyday life and psyche. I could not agree more. I did not find my actual therapy very useful as long as it lasted but all the reflection, revisiting, discussing it with peers, applying whatever comes up mentally to everyday decisions has been extremely useful. Why I also keep coming to this forum, in part (the other parts are curiosity and entertainment). I like to say, especially when I am feeling a bit too full of myself, that I have done it all by myself... technically perhaps, but not without significant external influences from many different domains of life, and I think therapy played a role as well, just not directly.

So, if you feel lost at how to use therapy constructively, maybe try to open up your mind and supplement it with other new things. Also, people often say therapy takes a long time to be effective and you may not even notice it's working in the moment but perhaps you have already grown from the experience some at least? I think this "real change takes a long time" is true for many things, not just how therapy can work. You may be familiar with how challenging it can be to change even a single bad habit if you have ever tried to overcome one?

Finally, I would second unaluna's points about interaction. I don't think it has to be attachment at all, but interacting with the world and other people does help. We can easily become quite misguided and even delusional (including about our own powers) without interacting with the world and human realities. Maybe some people are truly resistant to it and are perfectly happy/efficient on their own, but most of us aren't that way. I am definitely not and, from all I have seen about you from your posts, you don't seem truly satisfied without interaction and relationships either - you can perhaps just suppress it for a while, periodically. But we discussed similar things on some of your earlier threads already. Attachment is a loaded word, especially on this forum, and I don't like it much because people mean many different things by it, some more in the realms of obsession than healthy attachments. I think interaction is better.

As far as EMDR, did you have specific, more isolated significant traumas that still bother you and hold you back? More distinct events than chronic non-events? If yes, I believe that's what EMDR is designed for.