I see your symptoms are different from mine and you're much more knowledgeable about the brain. I'm very sorry that I'm not able to answer your questions. To be honest I'm not even sure I fully understand what exactly you're going through. So I'll just simply tell you what is helping me and what difference I see. Hopefully you'll be able to take at least something from it.

I was completely stuck and immobilised /frozen after life long complex trauma and basically unable to begin my independent adult life. (finished uni at 25 and my first real job at 27 was a massive failure - I taught at primary school where I was basically bullied by my students while my mother was battling leukemia). After a year of this I only worked in the family business and lived like in a fog or dream, with no emotions, only negative ones.

I found out about complex trauma when I was 29(last year) which came as a huge, massive relief and simply having a diagnosis gave me hope and strength to fight. I found an online therapist who walked me through exposure of my trauma. I have two sessions a week. It was extremely difficult and I was on an emotional roller-coaster but I allowed myself to feel and cry. I'd been suppressing crying for about 20 years before. My T says it's very important to allow yourself to feel the emotions and "sit with them".

What helped me from somatic experiencing was imagining that I'm in the traumatic experience from the past and I allowed my body to finish the action it wanted to take. For example I was in a situation where I wanted to run or fight but wasn't able to. Now in the safety of my home I allowed my body to run and I imagined the fight including real physical movements. You imagine running into safety or winning the fight. This should rewire your brain and release the stuck energy. I don't know if this happened but I did feel better afterwards. I did pendulation as well.

Mindfulness - I've been practising body scan and mindful living (on my daily walk, doing chores, when I'm cooking, when I'm showering) since the beginning of August. I feel much calmer and my focus has improved. I'm able to manage my anxiety better. It's not ideal but I'm surprised how soon I see the difference I want to keep doing this.

I also did art therapy by drawing my trauma experiences.

The combination of these has led to significant release of both positive and negative emotions and stuck energy. The beginning was extremely difficult, I could cry 2-3x a day for a few months. But the more I cried the more I was able to feel good and positive emotions, too.
I'm not healed yet, but over one year I made significant progress, found new hobbies, I began going on trips, improved self care and was able to increase my workload slightly. I'm now in the point when I think I might be able to move away and begin a real adult life sometime next year. I'm still quite socially isolated though but I don't mind. I'm much more active and go out more often even alone.