What do you think psilocybin is? Any drug that has psychoactive effects is a chemical.
I sure hope you didn't mean to say that you were tripping off the chitin, the fungal monomer tissue and not the highly hallucinogenic chemical that's found in it. The chitin is why mushrooms give stomach aches, because the pepsin in our stomachs have difficulty digesting it.
But really, if you made it into ginger tea your stomach wouldn't have had a hard time, because you wouldn't be ingesting the chitin fiber and ginger does wonders for upset stomachs. And you would've been okay drinking because alcohol generally relieves trip anxiety.
Lastly, if your idea of a bad trip is puking then passing out, maybe you should stop doing psychedelics.