This is my first time experiencing it, but all things are influenced by so much that is unseen. There's so many factors that can influence a bad trip, which is why it does really pay to always choose a safe environment/group to do mind altering substances with, but sometimes life just occurs. I really want to do shrooms again, as my first experience was...relatively enlightening and calming, overall.
My Mother's people, the Purepecha (Tarascans) had Mushroom Cults , that had trained Women administer the dosage to the participants at the ceremony. I guess the OP, found out the hard way, why Mushroom Cults had experts give the proper dosage.