Zegh, those sort of psychedelics can indeed produce some life-like experiences, and entity-contacts. I can testify to that personally.
And you would have to take a MASSIVE (with respect to an active dose range) quantity of acid, just look at the way people in the trade have done thumbprints. God knows how much acid that would get into your system via a thumb print, which is what it sounds like, dipping a thumb into crystalline LSD, but its bound to be an absolutely thumping great dose.
I've had a trip on morning glory seeds before where I relieved part of a battle during a war, through the eyes of one of the combatants, but never believed I WAS that soldier, it was more like a first-person perspective view, from behind the eyes of a second person.
For the really immersive, detailed experiences that can happen like that though, the serotonergic psychedelics, aren't really the ideal candidates, but dissociatives like ketamine, PCP (which I haven't tried, only quite a lot of substituted PCP analogs, PCE analogs and such), those can indeed produce a 100% full on in-your-face believable scenario. But it does not persist past the duration the substance is active.
One can certainly loose it on uppers, speed psychosis generally happens when the user keeps pushing and pushing the boundaries of how long they can remain awake for to do more of their chosen substance, its got a lot to do with sleep deprivation. I once accidentally did so much whizz after coming home from a party where alcohol, pills, ether and other things besides were going around (I'd brought the ether, as well as some yopo/cohoba snuff, other people were contributing all sorts to the gathering)
On my way home, I got a lift to see the dealer from my friend's mom, to pick up some speed, did several grams over a few hours, but unlike usual, in this country, a lot of amphetamine sulfate that goes around is cut so badly, or at least it used to be, haven't bought any in quite a long time, that it was maybe 5-10% amphetamine, the rest glucose, caffeine and god knows what else. This stuff was absolutely mental strong 'base', which is a slang term for a gooey, kinda oily-pasty strong smelling speed that can be a blow your head off degree of strong.
This did, and as I remember, I started just going off into microsleeps for a second or two according to others. Didn't sleep properly and fully for a couple of WEEKS after that party, thanks to the monstrous comedown from some of the things imbibed, and that phet keeping me wide-eyed and sleepless.
Started to see things at first out of the corner of the eye, and as time passed, eventually it got to the point where I was taking a shower, and seeing vines sprouting and writhing, out of a big black vortex upon the wall. Was all kinds of flavours of fucked-upness.
These days if I'm doing amphetamines, coke, research chemical stimulants, stimulant plants and herbs of any kind, unless pretty mild, or taking a low dose, I make sure I time my use to just before the day my repeat prescriptions come in, so I have a good amount of wiggle room to knock myself out afterwards with as many sleeping pills/opiates/muscle relaxers as needs be to turn what would be a comedown into a nice relaxing day in bed instead
No, you won't, definitely won't, ever, ever, turn into a glass of orange juice in a mental home for the rest of your life, thats propaganda and nothing but.