Hello! I enjoy a good dramatic, dark, relentless story, though, I know it can also be overwhelming, and tough, to continue trudging through page, after page, after page, of incredibly cruel, daunting, and heartbreaking story for most people, including the writer while writing it.
From what I've experienced while reading, writing, and enjoying other people's works, it could be as simple as inserting something unusual, or out of place; Describing it for a paragraph before continuing on. Sprinkle it in, letting the people have their sips of water.
EX: A hell-scape of souls, tormented, and writhing in pain as the scream and wail, forever in the apocalypse of death and misery devouring the land of (insert random world). Our hero, crying, and terrified, having just lost his parents, and family, and sister of whom he cherished like no other, slowly feeling as though he, himself, was perishing under the scorching sun, breathless, and tired, wanting to surrender his life to the gods who ravaged his land, his home, turned and saw, of all things in this desolate waste, a flower.
Describe the flower, its color, its hues, the number of petals. name the flower. describe how the flower moved in the soft gust of fiery wind. how it felt to touch. how it smelled. Just a few lines to give the reader a breath of fresh air. and carefully, let the flower go. watch its petals, or the whole flower itself, fly off in the wind never to be seen again.
continue with the story.
I think Moby Dick did that, but in more extreme passages, diving headstrong into the madness of the captain's obsession of the white whale. Chapter, after chapter, of hunting, and lusting to see it dead. and then, random chapters talking about boats, or the sway of the sea, or just the insignificant seagulls soaring overhead. Lengthy inserts that felt like nothing; Jump cuts that had nothing to do with anything, just space to breath, and regain some sense of stability; Maybe even to pull the writer back toward his own humanity.
I'm also currently reading a book called Nevernight. Between chapters of an assassin, one moment, talking about the gruesome murders in detail, to describing metaphorically, and physically about s*x, to the next chapter of being hunted by soldiers that want to mercilessly capture, maim, and kill them, to a memory of, simply, playing with a small cat. All short chapters, each having tensions in their own specific way; Some lighter, some darker.
It really depends on what kind of writer you want to be.
1. Tell it how it is, no reprieve, no cuts, just full heart on your sleeve kind of story. Those with strong wills to press forward will love it.
2. Tell it in chapters, going from one extreme, to the other. A gory, dark story hidden within something softer, and lighter between chapters. There will be those that, either get confused, or can't follow along, to those that will enjoy the story, and understand where the character comes from while also understanding where they're headed.
3. Or Tell a story with small, minor sips of hope sprinkled in, to have those unable to keep their eyes open, able to push through.
I'm sure there are other ways, but I'm also not a professional writer. lol
4. Lastly, don't worry. Write how you write. Do as you do. I know there's a want, and a need to look back at older chapters, but don't. Continue your story, feel it, dive yourself into it. Sometimes, you'll amaze yourself with what you can create. In the deepest, most vile, disheartening pits of slithering darkness, the smallest of lights shine like a beacon. Tell your story, and when the time comes, whatever tension, whatever broken character comes crawling out, when things hit the fan, and they finally stand up, you'll know it was all worth it. Goodluck, hero.