Bread

When you're so tired you feel like dried out bread.
This expression is taken from the spongebob meme of squidward looking dried out with text above him saying "Let's get this bread", alluding to being very tired, yet still trying to do work.

"Dude I was up all night, fell asleep at 8 AM and woke up at 9 AM for school, I'm so fucking bread rn"

"I've been awake for 23 hours, I'm bread'ing rly hard"