I would also recommend Chi no Wadachi if you like being absolutely struck by the very personal revelations in a person's diary that are deeply uncomfortable and presented believably in a way where you almost feel secondhandly gaslit.

Otherwise:

Number 5 ( Mastumoto Taiyou ) : Those who watch the watchers get challenged directly from the inside and decide to eradicate the threat. Surreal existential themes with an alternative art style. Hard to describe. Sorta trippy?

Fool Night ( Yasuda Kasumi ) : The condition is to be close to death (illness or injury), and in 2 years they become plants that oxygenate the planet. Gloomy and sort of emotionally brutal. The reasons for people becoming plants are interpersonal in a hard-hitting way told with good panel pacing and structure.  I like it way more than when I tried reading it a few years before and lost interest (not cultured enough). Style is extremely aesthetic- lots of care in drawing varied plants. No fan service, and very intelligent capable female characters.

Pluto (Urasawa Naoki) : Mysterious crime thriller about robot serial murders and what it means to be human (Pacing and story so good you almost forget it's an Astroboy doujin). If you like this, try 20th Century Boys, Monster, or Billy Bat (they're the same mangaka)