It sounds like you may have had an experience, to some extent, of dwelling in the union of wisdom and emptiness or what some call dharmadhatu [2]. It's not a teaching I encountered until I started practicing Vajrayana, as Theravada teachers don't often emphasize the teachings on sunyata. It's something you'll encounter in Mahamudra and Dzogchen teachings.
[1] https://www.shambhala.com/cutting-through-spiritual-material...
Ah, the extent that some people will go through to avoid acknowledging God. It's like some people take stubborn pleasure in being purposely nihilistic and strenuously denying all that's good about the world. How this can be part of a supposedly spiritual practice, I just can't understand.
That sense of impeding doom is nothing more than those spiritual entities oppressing with overwhelming power them by those gaps.
We are locked out of that world for a reason. The safe means to get unlocked is by getting your soul to borrow the power of God and slowly expose yourself to such world. Other than that, self enlightenment is just wishful thinking of empty vessels.
Our intentions, understanding, morality, sense of self, sense of direction, is so frail. A man who believes he can manufacture these things for himself (which is, in my opinion, wfundamentally what occultists are doing) is doomed to spiritual sufferring.
"Emptiness" of your mind means something like a thin soap bubble around you. This bubble acts as a lens, it can enlarge arbitrary things, it can create stable patterns on its surface, and all that is useful, but it blocks whatever is outside the bubble. In its natural state it would be a perfect invisible sphere, letting you see outside: this union of clarity and emptiness creates wisdom. You are still going to use this bubble as a whiteboard for your thoughts, but you'll also know how to see thru it.
The concept of emptiness applies to material world in general: the western science calls it space-time, the idea that any thing can turn into any other thing, for both are fundamentally just motions of energy that has no natural shape. Buddhism tries to teach this basic idea in different terms.
For some reason that I don't quite understand, the founders of the three religions had fragmented the truth: buddhism teaches wisdom, christianity teaches love and islam teaches action - the three aspects of the spirit. Perhaps they thought that mixing everything into one bag would be too difficult to grasp, or maybe they hope it will make the peoples collaborate to assemble the pieces.
I also would point out that if anything Buddhism is life-affirming and immensely hopeful, not denying what's good in the world. It teaches that there's a way out of suffering right here and right now, and it's available to every being without exclusion. The fourth noble truth is the spiritual practice to make that happen. Every meditation session in Mahayana and Vajrayana lineages have the common preliminaries, which includes love and compassion for all beings.
https://untetheredsoul.com/untethered-soul
https://untetheredsoul.com/living-untethered
I also found eckhart Toll's book "A New Earth" are also helpful:
https://eckharttolle.com/books/
I found "A New Earth" better/more details than "Power of Now" probably because it was written later and I read it later.