the.com/tedious
The feeling of time gaining weight while nothing happens.
means So dull and drawn-out that it actively drains your will to continue.
from From Latin taedium, meaning weariness or disgust — the same root that gives us tedium, time's heaviest unit.
Sibling wordShares its root with tedium and taedium vitae.
Literal senseLatin taedet meant it wearies, it disgusts.
Spelling trapThree syllables, not two: TEE-dee-us.