Aionios at his best.
I'm not going to try to answer - it's way too difficult for me - but I want to quote a passage from a novel by Sebastian Faulks called Engleby. [The whole book is written in journal form]. When I came to this passage last week I thought immediately of you mostly because of what he says about the nature of time (which I think is crucial in all of this) but I'll quote the passage in full because it's such wonderful stuff. If you don't have time for the whole passage go to the bit in bold.

from 'Engleby' page 154 - 155 (pub. Hutchinson)

A lot of time has passed.
Is that good? I never know. I haven't stopped to reflect and write, and that suggests that I've been busy.
Busy is good, isn't it? Busy means we're hard at it, achieving our ends or 'goals'. Haven't had time to stop, or look around or think. That's considered the sign of a life well lived. Although people complain of it - another year gone, where did that one go? - tacitly. they're proud. Otherwise they wouldn't do it: you put your time where your priority is.
Suppose, though, you're not sure what you're doing is at all worthwhile. Suppose you blundered into it over a spoonful of lime pickle. It's easy, it pays quite well. But it's really a distraction. It stops you thinking about what you ought to be doing.
Because what you really ought to be doing is weighing up the facts. If the history of Homo sapiens so far were represented as a single day, an average human lifespan would represent a little over half a second. That's your lot, that's all you have of living, then you return to the unconscious eternity that came before and will close back over you - over your half-second. If the whole history of the earth (not just the brief Homo sap era)were represented as one day then your existence would be too small to measure. No sufficiently imaginative chronometer exists.
So what you must do - being an intelligent, thinking creature - is make a very careful, well-informed judgement about how best you can spend your one and only half-second. You analyse yourself and your abilities; you match them to the world, its ways and possibilities, and you make a solemn decision to do what would most contribute to the well-being of the world and of yourself.
Except you've got a deadline, Friday at noon. And your lover coming round on Tuesday. And there's football on.
This 'busy' thing isn't a commitment, it's an evasion.
And what are we avoiding? Facing the problem of the one half-second. Because if that's really how it is, if that's time, then nothing is worthwhile and nothing makes sense.
If time is not really like that, then all might yet work out. And in fact - good news - we do believe that time is not linear. The trouble is - bad news - that our brains can only think of it as linear, therefore we're doomed to see our lives as pointless.
It's funny, really. The most intelligent creature that's evolved so far (we think) has a design flaw at the heart of its superior intelligence. It can't grasp one of the dimensions it inhabits.
It's as though we had longitude, but no latitude. How then would we navigate or reckon our position on the earth?
We're deaf men working as musicians; we play the music but we can't hear it.

I'm so tempted to spell out what I think about this and how it relates to what you were asking but I'll resist because I know I wouldn't put it well enough and it would seem trite to you.
best wishes ng