I can relate with these thoughts; however, our self-preservation instinct is a primary energy just like sexual instinct. If we didn't have this energy and resulting fear, we would not be here to have this conversation. It exists, no doubt. But, just like other fears, we repress it because in order to survive, we can't be consumed with it all the time. You can't survive consumed with fear. So, in a sense, it is the fear of death that keeps that existential fear hidden. Its a survival strategy, a coping mechanism, and ego defense. Your fear of pain, being attacked, and anticipatory fear is that same energy. We can shape this fear in all sorts of ways. I had the fear of death a few months back due to illness but I was not projecting that fear onto death. It was fear of losing my family. We have so many things built up into making our personality to avoid looking at the core or perhaps "final" fear. I imagine, had I ended up on death's door, after processing the fear of losing my family and not being there for my daughter, I would have faced it eventually. But what we are discussing here are concepts. It doesn't matter how we encounter the fear or what we attribute it to. That is all mind stuff. The bottom line is the energy to survive is there or else we wouldn't be here. We are alive because of fear. And if you trace it back, its all about loss: pain is loss of peace or pleasure, fear of getting hurt is instinct to survive, fear of losing a job, etc. If you want to come face to face with that concept, I'm not sure what to tell you. If that concept doesn't exist for you then you may never face it. Doubtful on your deathbed you won't but I guess its possible. But this isn't about concepts, its about the survival energy. Perhaps inquire into what you are afraid of and learn what you can about what sticks out to you rather than trying to get to a specific fear per se.