oh yeah I feel you. I was really successful in my professional life, but actually never connected to myself. Basically on auto-pilot, but I was "fine" as I did not know anything different.
In the last weeks I have the first moments in my life, where I feel safe enough to really experience the beauty of nature. In these moments, I feel so much exhaustion in my body and my brain. And so much pain in my body. This stays for some time and then slowly I build up my guard again and detach from my surrounding. I start to realise that I am actually afraid of people and it is not yet possible to stay connected outside. I feel then, how I slowly lose the connection and my brain starts to produce anxious thoughts again and anxiety rushes in my body. I always feel I am losing something really precious again. I lose myself again....
I was have the same topic with loss and I actually lost someone really close which overwhelmed me. When this gets triggered it is an unpleasant spiral and it overwhelmes emotionally.
I also had my "professional" persona, to rely on for a very long time. Basically, I was using some socially acceptable obsessions (workaholism, losing myself in a particular field of work, or a topic, or a relationship etc.), so that I would not deal with me. I was often quite successful professionally, because I would throw all of my capacities into it, to an extent that most people find unattainable.
I find that it is wonderful that you can connect to the nature, even for a while. I understand that there must be a passage that opens for your emotions to come out, but as they overwhelm you, you detach again in order to protect yourself from the pain. Re-connecting with emotions must be like learning a new language or a skill for us who were emotionally detached for most of our lives. I firmly believe in learning, as you can see, lol...Letting ourselves feel and learning how to articulate the feeling may be our biggest achievement yet.
I am very sorry for the loss you experienced in your life. I never ever let myself experience the loss before, even though I had it, just as everyone else. For as long as I am aware, I would just erase everything that was too painful for me to bear, or to put it more accurately - I would compartmentalize my memories, and push a lot of stuff behind amnesiac barrier. The fear of the emotional pain is so basic in me, that I go lengths to negate either myself or the reality, hence - depersonalization and derealization. When there is no DP to protect me from the pain, my mind starts playing with suicide ideation, because it is still easier for me to imagine that I am gone, than to feel the unbearable feeling.
However, that really robbed me of a lot in life, such as experiencing life to the fullest, and most of all - just as you say - it denied me feeling as myself for most of my life. No matter how horrifying it is, I want to go into that emotion, and I want to feel it without shielding myself with all the coping mechanisms that I have in abundance. As I have often encountered being said before: the child had already survived the trauma, now the adult has to face it/feel the emotion behind it. If it didn't kill us then, it really should not end us now, I guess...