Sense of realness is probably a function of cognitive coherence.
I'll try not to get too technical, but bear with me. To illustrate... there is a neurological condition called
Capgras syndrome that causes people to believe that the very familiar person they are with is instead an imposter. This is caused by a dissonance between succesful recognition of the person and the missing emotional charge that is supposed to go with it. Apparently they discovered that there is certain coherence lost in the brain, activity that is supposed to be triggered in the IIRC amygdala is 'missing'.
You would expect to feel things like a sense of security and familiarity and so many other things that you associate with a person very dear to you. If you don't, that apparently causes paranoid feelings and ideas: something is not right. Things aren't real, people are imposters, you are being fooled, et cetera. The effect is: it certainly looks like it is e.g. my very close friend, but somehow I feel it isn't or couldn't be him.
That is why I think that if you, spaceface14, are missing emotional associations, the feeling that things make sense and are real and right... the cause might be that certain connections in your brain are interfered with and the activity is (hopefully and assumeably) temporarily changed or more scattered / less attuned. I believe for some reason the drug may have caused some kind of disruption, it will probably take a little time before the activity over those connections is more or less restored. The best explanation I have is that your brain is giving you mixed signals when you are looking around you... so while that is the case hopefully you can help yourself by artificially introducing some reassurance, when you reflect on it. It may help to try and reconcile what feels like it is not making sense, I realize that may be a hard thing to do though.
Although things are always changing in the brain, you can never really go back to how it was... but you can hope to see similar functionalities return. Usually you can be very hopeful about it, these NBOMe's are a bit of a new phenomenon though. Have faith.
Psychedelics changing the coherences that make (part?) of our brain activity is nothing new, I think... but you have to
really push it to cause lasting effects. NBOMe's with their high receptor binding affinities just might be more extreme than we are used to, and this may translate to thing like what happened to you, getting HPPD a whole lot easier, and more manifestations of brain coherence getting fucked with.
Also some people are probably more sensitive to others, so that might make matters worse or problems / risk calculation more unevenly spreaded...
disclaimer: I am not a neurologist, just theorizing out loud.