Hi, I'm late but I'd love to answer your question.
Look, some time ago I would have identified myself a lot with that. But today I see how it makes no sense to think like that, I mean, ARE WE HERE, RIGHT? I AND YOU AND THOUSANDS OF PEOPLE IN THE WORLD AND THERE SHOULD BE A SENSE FOR ALL THAT. And as much as we do not know (and probably will never know) it is important that we look on the other side. These thoughts will not help you in your recovery, they will only sink you deeper, I mean, how could they help you? So after I started to think like that, after I started to stop looking for meaning in life and tried to make sense of it, everything changed.
It is common to have episodes of depersonalization when you are anxious, especially if you are curious and want to frantically find out everything about everything. The origin of life. Take it easy. Because you will not get there.
In my case I wanted a proof at my feet that God existed. So I, being unable to do worse, decided to search for reasons to believe and not believe in God. And everything, ABSOLUTELY EVERYTHING, about both beliefs made sense. And it started to eat me up and eat me alive. I was in such a big crisis and I did not know where to run. But one day, I decided I would take it easy and, talking to other people also got the help needed.
From what I have read, your case is more to the derealization than the depersonalization itself. Although it could be both. Research it.
It is very common to feel this, studies say that everyone will have at least one episode in life.
Just try not to feed those thoughts.
But anyway, I think what I have to tell you is this: Take it easy and I'll be here if you need to.