According to David Nutts study psylocibin is regarded as one of the least harmful drugs. I have also seen a study showing that use of psychedelics was associated with lower rates of mental health issues later in life.
http://journals.plos.org/plosone/article?id=10.1371/journal....
Sounds to me like it put a crack in your ego rather than a crack in your sanity.
This is what many so called psychonauts do not understand.
A bad trip can be traumatic and can revive other traumatic experiences.
https://www.verywellmind.com/ptsd-triggers-and-coping-strate...
https://www.reddit.com/r/LSD/comments/630i1g/trauma_from_bad...
Psychedelics can lead to decreased wellbeing, decreased psychological and emotional stability and decreased strength and robustness to deal with further stress and unpleasant challenges.
Medical experts use psychedelics because of their strong destabilizing effects.
Nothing is gained and much is lost if this uncomfortable weak unstable state remains.
Set and setting is important. Do not try psychedelics to solve problems.
But set and setting is not everyting. A bad trip might happen anyway.
Who knows about its genetic, biological and psychological constitution and reaction before the trip ?
That is why a medical expert as trip sitter is so important.
"Despite these difficulties, it is notable that 84% of respondents reported having benefited from the experience, with 76% reporting increased well-being or life satisfaction attributed to the experience."
Study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5551678/