I am convinced that on everyone's deathbed, they will finally realize that they are all lies

Reading the OP before replying to it, while not mandatory, is highly recommended.

"Every single person in this world, when on their death bed, will feel as if everything they lived for was a lie."

but I definitely will feel betrayed by life.

Others also include gods

about all sorts of stuff: I'm been trying to make it more of a habit. I guess if it becomes habitual enough, it'll be something that I might automatically brood about, if I'm ever sitting around dying with nothing else to do

...I believe very strongly that on my deathbed I will finally gain an accurate sense of proportion: That is, what I spent much time and effort and anxiety on that really matters very little. And that which passed by me unregarded at the time but is of deep significance.

I hope I retain enough wits to be able to laugh about it.

thoughtfully,
Bright

...as they die. If you die a sudden violent death, such as having a large, high-velocity bullet passing though your head, there would be no time for anything but a few confused milliseconds, after which all thoughts would cease altogether. If your brain slowly loses oxygen I suspect that one's last thoughts are very much like the thoughts reported by those who manage to come back to full consciousness after very nearly dying.

As no one who has truly died can report their experiences, this subject matter is all speculation. I see no grounds for being "convinced" of anything at all.

Read "A Diamond in Your Pocket" by Gangaji. She talks about how our egos distort our True Selves and how most people never discover their innate bliss until the moment of transition!

who realizes the meditation on emptiness, (spaciousness) and has been set face-to-face with the Clear Light of Primordial Awareness as the Dharmakaya, that would probably not be the case.

In fact, such a realization is of the non-dual, unborn, deathless, timeless state of the unconditioned. So, death would be a part of the play of energy from said.

Lots of people have become unconscious at multiple points in their life.

The only difference is that you don't wake up.

staying conscious long enough to have realizations of any sort, much less existential ones. For the last couple weeks of her life, she was asleep 95% of the time, and basically woke up only to be walked from her bed to her chair (or back), and maybe to drink some water or take some meds.

The realization that life is a self-constructed illusion is a liberating moment of "death-within-life" that confers both perspective and peace of mind. There is no need to wait for it.