In a sense all experience is personal. My seeing something is not your
seeing something. But what we see contains our bodies and through
means of them we communicate and we communicate about what we see - at
least to some extent. In the same way we experience the meaning of
things and we can communicate about that meaning. It is factually true
that there is a lot of commonality in what we experience in both fact
and essence although it is not complete.
So the situation with respect to whether it is a personal experience
is not different for religious and non-religious experience in that
sense. If you read the records of those who have had religious
experience there is remarkable but not complete agreement about what
was experienced as is true of all other experience. (In another sense
religious experience is "deeply personal" meaning it affects ones
identity and bears on ones desires in ways that some not religious
experience does not. It is more like love than science and in fact
there is a relationship between it and the experience of love that is
not there in scientific observation)
Now you have characterized it as "psychotic". That is not a neutral
word. It is also a very modern word as you did not just use the word
"crazy". It is more like the kind of word that someone who has not
experienced it has for those who have, although you say you have had
such experience. In fact religious experience is usually characterized
as understanding for the first time. It is possible that what you
experienced was not religious experience but genuine psychosis. It is
sometimes not so easy to distinguish as many psychotic episodes have
religious content. It is also true that some psychiatrists sometimes
cannot distinguish and I know of one individual who was medicated
(Haldol) for trying to communicate the content of his religious
experience. Also you have said "everyone who goes down these strange
rabbit holes comes out the same". That again is not a common
observation. Most report profound change in their interpretation of
life. I know of one individual who changed from a economics major to
an art major because of it and his future life was changed. My life
certainly has changed because of it.
Anyway however we might interpret these experiences one thing seems to
be sure. They are reported independently in every culture in every
generation. (Actually I can't say every one because I have not
examined them all). The real situation is that many cultures do not
have science and cannot distinguish interpretation of their religious
experience from scientific observation. For them, as it was in western
culture long ago and in fundamentalism today, science and religion are
mixed together and discussions of causal origin and the meaning of
being get confused with temporal cosmology and evolution. This mistake
is an equivocation of material causality which is an essential reality
(a scientific fact if you'd like) with causation ex nihilo which
cannot be scientific and is not essential. The problem is compounded
by the fact that brain function is materially necessary for
consciousness scientifically and compounded also by objectivity which
can be interpreted existentially instead of as an essential contingent
fact. So it gets really complicated intellectually to sort it all
out.
To me the two big mistakes are first to interpret religion as a kind
of science and the second mistake, that usually precedes the first is
to believe that you can choose what to believe in by making a personal
decision and sticking to it. The latter is the worse problem.
That fact that in a sense you can do this implies that you can lie to
yourself and that is the biggest problem. You can just get off the
track of trying to understand and decide that it is "good" to believe
xyz and choose to believe it abandoning any further intellectual
pursuit or questioning. You then get to join a church and have all
kinds of experiences you wouldn't have if you kept trying to
understand and refused to say you believed. Many churches are set up
precisely to pressure one or influence one to "confess one's faith" or
"accept the Lord Jesus as one's savior" while all the while these are
code words for getting you to abandon your questioning and get on
board the organization. Check your wallet. It is a good way to
distinguish the genuinely religious from those that are not. The
genuinely religious will not be accumulating lots of money as they
will use it on the needs of others.
The difficulty of the genuine pursuit of truth aids in making the
decision to abandon it as this stuff is not easy to understand without
a lot of careful, one might even say painful, study so the choice is
often to believe xyz or to say "I just don't understand". Also being
one of the ones who "knows" has social consequences and whole churches
are set up to reward those that run them. It is also an ego thing to
know. For them to admit that they have no genuine religious experience
is to admit that they are a fraud. To do that to others would be
relatively easy. To do it to themselves is what is unfortunately hard.
Therefore the most important thing is not to let go of your critical
ability too early and just believe what someone says. The material is
hard but in the end it is understandable somewhat at least. If it is
not it is not real. At least progress can be made. Abandoning the
pursuit prematurely is not profitable.
Good luck to you.