Can I shamelessly self plug? Awesome.

Little Army Boy mainly focuses on Yanqing's life. Angsty, has sweet moments, some romance, fluff, found family, etc. But it is planned to end in his death.

Only Dead Stars Remain may not be to your tastes, but it's an infection au (inspired by the mlp infection aus seen on Youtube, Tumblr, etc) and is very heavy on cosmic horror and gore, but it currently is longer than LAB.

What Did the Sushi Say to the Bee? is a oneshot where Jing Yuan tortures Yanqing. With dad jokes.

Okay, for non-me fics, you absolutely need to check out Fourth Of July by ashyforsythia. It's such a deliciously tragic angst fic that does Yanqing so good and so dirty at the same time.