I agree that, while on LSD, thoughts are hyper-symbolic. How they come to be so symbolic, I don't know. Decomposing a sentence and reinterpreting each word is one way, but I don't think it's necessary. For example, on LSD I have pointed to something with a clear thought in mind, only to find that a fellow tripper interpreted my pointing a completely different way. My pointing in this case was symbolic for many different thoughts/meanings, so even words are not necessary to experience such symbolism. I think a focus on language is normal for an LSD experience, but that language can be anything: It can be words, gestures, tapping, tones... anything that must be interpreted (even just physical objects) can be misinterpreted, and I suppose that this misinterpretation is somehow the cause of all discovered (i.e. accidental) symbolism.
Regarding the story about pointing: at the time, even I forgot what my original intent was. In psychedelic social situations, every person's mind is diverging from any given topic all the time, so I agree that it's incredibly hard to nail down any particular thought in your own mind, let alone in a conversation with others.
I think this simultaneous hyperactive desire to communicate and inability to communicate due to motor/mental inability is what results in certain "conversations" with "God"/reality. If we can invent a being intelligent enough to understand our divergent thoughts, then we can imagine a conversation with something that understands us despite our own inability to understand and communicate. When we are finally understood, we can stop overthinking, hence we can be at peace. I think this is only possible when our uncontrollable urge to communicate is satisfied by such a hypothetical being.
Every day I am thankful that I was introduced to psychedelic drugs.