Psychedelics are often said to simulate many aspects of schizophrenia and other severe neuroses. I would argue that intense psychedelic experiences also approach psychosis, in the psychoanalytic sense of a mental state where normal symbolic reasoning is impossible.
I wouldn't interpret this as evidence that there is something wrong with your brain or anything. Rather, I would say it provides an insight into how even the 'normal' mind operates in fundamentally the same way as the most deeply psychotic one. A sane, well-adjusted person differs from the deeply neurotic one not by having a 'healthy' brain, necessarily, but by having a more stable relationship to his or her own emotions, memories, traumas, insecurities, etc. Western medicine has constructed a very flawed understanding of mental health, where people think they are either healthy and 'normal' or there is something wrong in our heads that drugs or surgeries can fix. While there are certainly people who need drugs or surgeries to correct these types of conditions, that is not the case for most neuroses. Ultimately, we are all neurotic; it's just a question of how effectively we can deal with it.
I rather like azzazza's comments on this (probably because it's also a psychoanalytic approach). Think of the thoughts and revelations you have on psychedelics less as insights that are either objectively true or false and more as repressed content from your own unconscious. It's there to signify _something_ - a thought, a memory, a connection you have made in your mind - but it's not necessarily what first comes to mind, or the obvious literal meaning. If you hear a voice whisper some strange word to you, it doesn't mean you're a schizophrenic who hears voices and you just didn't notice before taking psychedelics; instead, I would try to think of any connection you can draw to that word, or any experience it reminds you of. Much like a dream, the actual meaning can be displaced into a misleading form (maybe the voice itself is the content, or the act of it being whispered, and the actual word is just filler; maybe it's the reverse; maybe something far less obvious than that). If a particular thought, image, symbol, etc. seems uniquely important to you, it's probably representative of something your unconscious wants to work through. Metaphoric condensation (where a single symbol stands for multiple unconscious thoughts or desires) is also a common dream mechanism. If you find this approach interesting, try googling for a copy of Freud's "The Interpretation of Dreams." If you're willing to go further down the psychoanalytic rabbit hole, Lacanian interpretations of Freudian theory are, in my opinion, the most accurate theories we have for interpreting psychedelic experiences.