An afterlife would be terrifying for me

[Belacqua]

so all your stories and ideas are going to reflect your present lifestyle and aspirations—unlimited supply of sex and food would do it without much worrying about predators.

The kind of afterlife described by Augustine, Aquinas, Dante, Boehme, and many others, doesn't resemble this at all. 

What argument can you present to show that their ideas originate in hunter-gatherer fantasies of comfort?

have started seeing the logical and scientifically clear flaws in the story.

I think you may have historical flaws in the just-so story you've told above. 

There may be logical or scientific flaws in the theological views of an afterlife, but you'd have to know what they say in order to address them.