The basic situation is this: you experience something in your life, which starts a learned reaction, which originates in childhood abuse. This "thing" you experience is probably an inner experience, like being happy, being inspired, being scared, etc.. It is probably different in everyone. You experience something in your life, which starts a learned subconscious mechanism in you.
Now, the learned mechanism I'm talking about, is there because you experienced emotional abuse chronically (frequently), and you responded to it by learning implicit reactions. Implicit means that you did not consciously decide to respond in a way, but just responded instinctively. This is why DP makes so little sense, because it doesn't have a "reason". There is no "reason" why you do these things, these are all implicit mechanisms. Emotional reactions that doesn't really have an "answer". You just experienced abuse chronically, and you just emotionally responded to it. And since this happened frequently, the response became automatic.
What is the result of this, is that every time you experience that feeling that initially started your DP, you start to solve problems that don't exist. This is because, since the original feeling didn't and didn't really have a reason (didn't have a reason but of course had a cause), you can not FIND the reason now.
To understand this, you really need to understand what the difference between a reason and just a "cause" here. I'm telling you examples. If your loved one dies, you feel bad. This can cause several feelings and emotions in you, but all because of your loved one dying, and you clearly know it. But if a psychopath approaches you and insults you in those subtle ways I was talking about in my previous posts, you can't really make sense of the situation, you just feel bad. When you are under psychopath abuse, all you experience is just a feeling. Not an emotion, just a feeling. You don't understand what is happening, so you can't point out a reason, but your emotional "sensor" just notices that something feels bad. If you don't understand this part, read my previous post about the girl and her mother eating her food off the table.
The main thing here, is that these feelings from childhood coming up in your life now, they are uncomfortable and even scary, but there is nothing really to solve there. But at the same time, you are a sane human being who KNOWS that when you feel bad, there is a REASON. But these feelings have NO REASON, especially no reason in the present, they are just LEARNED implicit reactions from childhood. So there is nothing to solve, but since you feel bad, you automatically try to solve this.
This is how you end up thinking you are going mad, lost yourself, etc.. Because you grab the feeling, and try to "solve the world" from that feeling. And when there is nothing wrong but you are STILL convinced (because your emotional sensor alarms), and still want to fix the problem, you will "fix" things that aren't broken.
Realize that all these weeks, months or years you have been suffering, there was not a single negative realization that would prove any of these feelings. You doubted your sanity a million times about a million subjects, but all of those scary castles collapsed. Every single one. All you did was causing yourself terrible hours and days, but nothing actually happened.
Hope I helped.