I tried psychedelic substances in my youth, and I've been pretty lucky and happy.
That said, i know exactly what you mean about being on the edge between sanity and insanity.
I regard that now as a precious experience, but it was scary.
It's difficult to define insanity, many people look very normal, then one day they wake up and they explode.. others can be quietly sad their entire life...
Also, there's undoubtedly a relation between genius and insanity, one could write entire books..
To answer your question again, I've been studying different beliefs/religions/philosophy for many years.
Now, for example, if Jesus says something, and Buddha says the same, and the animist American Indians say the same, i assume it to be true.
So, of course i am aware that my beliefs are debatable, and i regard " logic" as one best friend.