I was a bit hippyish a few years back and tried numerous psychedelics. I also kinda subscribed to elements of eastern philosophy, such as Buddhism and Taoism etc.
Mushrooms grow beside my house and I used to store them and take them in "heroic doses" now and again. Of course, holding a more positive outlook like I did, I thought psychedelics would perhaps have helped me become even more "carefree, peaceful" and all that shit...but actually, the opposite happened...

They showed me the horror that is existence.

I used to meditate in the countryside and I remember taking Mushrooms and even Marijuana and stuff into the forest to go into a deep meditation and every time, I arrived at a level of perception that left no room for sanity....truly a place to be feared. I entered a state of infinite emptiness, a solipsistic horror, a darkness within darkness. They showed me too much. Existence appeared nonsensical, insane, monstrous, absurd, nightmarish, like a disturbance in the void.

These quotes sum up the experience -

This world-appearance is experienced only like a day-dream; it is essentially unreal; it is a painting on void like the colours of a rainbow. It is like a widespread fog; when you try to grasp it, it is nothing. - Yoga Vasistha

There are no means for escaping this world
It penetrates even into your sleep
And is its substance
You are caught in your own dreaming
Where there is no space
And are held forever where there is no time
You can do nothing you are not told to do
There is no hope for escape from this dream
That was never yours The very words you speak are only its very words
And you talk like a traitor
Under its incessant torture.
- Ligotti

The human phenomenon is but the sum
Of densely coiled layers of illusion
Each of which winds itself on the supreme insanity
That there are persons of any kind
When all there can be is mindless mirrors
Laughing and screaming as they parade about
in an endless dream.
- Ligotti