Oh, wow.. Your style of writing keeps getting better with every article. It is obvious that you enjoyed writing it, which makes me enjoy reading it!

On the topic

I would say that most of the times I am Damian. I tend to keep negative emotions and thoughts for a longer time than I would like to. But here I would like to make a clarification or an attempt to add another perspective to your story.
Sometimes people feel/act like Damian, because of their self-observation, not because of cognitive impairment. (When I say people I actually mean myself also, because I am projecting at the moment.. Oops 😅)
Anyway my point is that sometimes too much self analysis and reflection actually makes you more anxious which leads to overthinking and reexperiencing negative thoughts and feelings over and over again.

Depending on what these thoughts are related to (could be something short term related like family argument, work problem, exam etc.) When that is the case the negativity and anxiety fade away when the event is not present anymore or lost it's significance.

But when these negative feelings and thoughts are related to something on the long term (traumas, personality problems) things are getting really serious and unpleasant for the one experiencing them. He actually becomes the victim of himself- his self-reflection the mechanism build to analyze and help him becomes an enemy, emerging suddenly then disappearing. This cursed circle of psychological process within a healthy individual (referring to your definition at the very beginning) could lead to some quite unpleasant conditions like anxiety disorders (Ocd, panic attacks) and depression.

Damian should allow Laura to appear more often, because her presence is healthy for him. BUT she can only do so if he allows her. If he is happy he would invite her himself and they would build a beautiful and healthy world (the person's complete fully functioning personality).

For me, Damian is mostly present, searching for answers in the negative emotions and thoughts reliving them and looking at them from different perspectives. After he is done, sometimes he discards them, but more often he keeps them locked into his wooden chest, because sometimes he thinks he would need them, transformed into defensive reactions to similar situations which created them originally. Laura would only come if invited or when she finds an opportunity to sneak in, while Damian is distracted. She would clean his mess and try to hide his wooden chest, but as Damian returns, he always finds it, chases her away and continues his work...