cooked

"Cooked" literally describes food that has been prepared using heat to make it safe or tasty to eat. Figuratively, it refers to a state of exhaustion or being in a situation where one is finished, defeated, or in serious trouble. Think of a piece of meat left on the grill too long—it’s done, perhaps burnt, and there is no going back. In casual conversation, you will often hear people say "I'm cooked" when they have made a major mistake or have too much work to do. It implies that the outcome is already decided and they have no way to escape the consequences. It is common in gaming and social slang to describe someone who has lost their advantage.
In conversation
A student looking at a difficult exam
Did you look at the last page of the test?
Did you look at the last page of the test?
Yeah, I’m totally cooked. I didn't study any of that.
Yeah, I’m totally cooked. I didn't study any of that.
Used here to mean 'finished' or 'doomed' in a stressful situation.
Friends discussing a burnt dinner
Is the chicken supposed to be this black?
Is the chicken supposed to be this black?
Oops, I definitely cooked it too long.
Oops, I definitely cooked it too long.
Used here in its literal sense regarding food preparation.
Examples
Make sure the chicken is fully cooked before you serve it.
Make sure the chicken is fully cooked before you serve it.
If I don't finish this project by five, I'm cooked.
If I don't finish this project by five, I'm cooked.
He realized he was cooked the moment the referee blew the final whistle.
He realized he was cooked the moment the referee blew the final whistle.