I have, for a long time been in awe of existence. I have sparsely had precognitive dreams since I was a child. These would give me an intense feeling of deja vu before they were played out before me in actually, weeks, months and in one case,
nine years later. The strangest thing is they are all mundane events. The scenarios in the dreams make no sense out of their temporal context.
I was raised by devout protestant christians. They offered few satisfactory answers to my questions about both mundane reality, and more philosophical, ethical and religious inquiries. Later I became agnostic, then Discordian. My philosophical views matured somewhat over the years especially with my introduction to Cannabis and S. divinorum. I found Sally to be of great insight and confusion. For a time I considered myself some kind of panentheist. However over time, exposure to multiple religious/mystical/philosophical traditions, psychedelics and my practice of contemplation, meditation and magic. I've come to realize Non-duality, (NOT DIALECTIC) is essentially the most accurate philosophical position I have thus far encountered for describing the nature of reality and the mind. I don't mean to sound overly sure of myself, but every major religious mosaic has a sect that has non-dual exponent. Also I have experiential evidence of this position, which is ineffable and so I will not try to explain it. Rather, let me explain how I came upon it. First I read the Principia Discordia, werein which everything worth knowing about anything and everything is explained. Then I read about chaos magic and other stuff and mucked about with cannabis and salvia. Then things progressed. I realized I had been chronically depressed essentially my entire life and did not understand why. Things stagnated.
My journey progressed with an existential crisis. I had a lot of things going on in life, I had just left my parent's home, to live on my own. Four days later I was hit by a car. Life seemed horribly unfair. I was broke, jobless and soon homeless unless I went to live with my rather unpleasant parents. They were not aware I used psychedelic drugs aside from cannabis.
I lived with them for a few months until I recovered. As I recovered I was immense pain. I read a book about mushrooms which mentioned psilocybin and LSD were some of the most potent pain killers \. I took LSD for the first time. It was Acid or Percocet. I don't like percocet. I hadn't tried acid. One hit couldn't hurt I thought. I had smoked S. divinorum extracts and leaves plenty before without much adverse reaction.
In three months (October, November and December 2009) I devoured somewhere between 30-35 hits of acid I believe were ~50µg over about 8-10 sessions. The culmination of which was new years eve, with 9 hits. ~450µg of LSD for an inexperienced tripper is not the best idea. Luckily a friend of mine, whom I did not really realize was an eclectic magician was present and helped guide me through the experience. I got caught in the loop for a while. I smoked an infinite amount of Chron that magically reappear in my lucky jar that survived my being hit by a car. No one rembered smoking but me, and they would say "we're gonna smoke now, that's what we've been saying...." and I would say we had smoke already, and behold a jar full of weed. Repeating over and over.
edit: upon further recollection I believe I also ate a number smaller doses between. I spent much of November tripping. This was dangerous. I do not recommend you emulate. 
I discovered a lot. Since then I have learned to induce trance states. In one such state, through a bit of focus, I can affect my own vision. Causing erratic visual distortions like objects breathing or morphing. Several others I trip with have confirmed they also can do so. This is due to a property of the brain kn own as
neuroplasticity. Essentially depending on how you use your brain the neural pathways, and dendrite connections' layout will differ. As will the neural pathway's purpose. The more practice something, be it a mode of thinking; a tangible skill like catching a ball; or reading a book, the more neural pathways are associated with that action. OCD has been shown to be completely curable, in that neruoplasticity can be used to counteract it. If you take psychedelic drugs, you may 'deprogram' yourself using the same principle. Especially if you were already in the process of doing so with various things like process art, chaos magic and surrealism.
The process has been long and it has taken me on a quest to learn what sanity is, because I think I can say I have never been or felt sane unless in a trance state something akin to what is called Rigpa in rDzog chen, and this seldom occurs in my base state of consciousness. I have been attempting various practices to achieve a bit of abstinence from constant immersion in mental constructs, and just try to accept what reality is in it's plain magical
extraordinary wholeness. There we go again with the mental constructs.
Zen/Chan Buddhism is interesting especially when contrasted with Tibetan Buddhism, Other Sraman and Veidc influenced practices such as tantra and post modern magical practices such as chaos magic and cyber craft (the latter having a distinctly wiccan/feminist feel, and little to do with computer or the internet outside of the typical 'technopagan' type stuff.
)
But ya, I'm on a quest to be sane. It's time to trip again because my adventures with sally stopped yielding fruit as I both offend her and refused to learn the lesson given to me more than six times. I gave up on trying to smoke her extract for the time being. I haven't touched anything other than cannabis in about 2 months, only Sally since new years. I don't drink alcohol or smoke tobacco or use any pharms. I like to Meditate, and sometimes burn medicinal incense for that.
I have been planning a ritual for some time. A camping trip were I and three others will take an admixture of herbs and either morning glories or mushrooms depening on which we can get in a timely manner. All of us smoke cannabis and have used Salvia. Only one has yet to try any other psychedelics. The other two are fairly experienced trippers and have experimented with a variety of substances. None of us have used DMT. I think myself and only one other are, of all the people I have talked to about it. Well, with the exception of one guy who would not try salvia, LSD or mushrooms, due to stigma, but wanted to try ayahuasca after seeing
this documentary. I think perhaps morning glories or perhaps mushies combined with rue or caapi might be sufficient for us... I dunno I ahve been reading trip reports and it seems to me DMT and similarly powerful visionary tryptamnies can easily lead to HPPD especially through such process' as neuroplasticity.
Like this OP seems like he might have undergone either HPPD, a case of neuroplastic reprogramming allowing for spontaneous psychedelic trance states, or both.
By the way, did I mention I'm dead? Yeah, well this one time I was alone in the woods. And I was just observing the beauty of the forest in a spot I like to smoke. I was smoking my pipe, tripping on 6 squares. I recited a koan: Tozan was weighing some flax. A monk approached him and asked "What is the Buddha?" Tozan replied, "This flax weighs three pounds."
Time no longer existed,
I no longer existed.
There was only this omnipresent awareness like a mighty buzzing nonbeing screaming at my senses this is
RIGPA, this is
Self. And I could see out of my own two eyes, and I could feel my bones in my flesh. But I was not this meat sleeve, or the identity it has accumulated. I could feel the expansiveness of my many bodies across space, time a probability. I felt perception expand beyond these and into to the forest. Into all physical realms. And I knew all that was and is and shall be. And then the infinity of the physical cosmos was a minute spec receding into greater interior mysteries of transfinite self-aware space that was a fractal vacuum of intrinsically beautifully, horrific absurdity that made me smile gleefully at the plight of the being which just perished inside that bag of flesh and bones that was fading from my present locus of awareness.
And then I basked in this sensation of being my
Self.
I do not know how long this state persisted, ten minutes maybe, no more than an hour.
I came out elated, laughed, and went home to research the subject. I eventually read about it a fair bit and foudn out the experience has many shades and names in many settings. Carmelite nuns call it "Unio Mystica" and it is accessible via many routes... Salvia is certainly one.
Well... I guess that is more or less my story. I came here for support and info on DMT, MAOIs, rituals and extraction teks and also because I see some folk here surely know about other subjects of great interest.
Anyways that is all for now I suppose.