Usage patterns
やけを起こすto fall into a fit of reckless despair
After failing the exam, he fell into despair and threw away all his textbooks.
やけ酒を飲むto drink to drown one's despair
He drank himself into oblivion after his heartbreak.
やけ半分に〈動詞〉to do something half out of desperation
I quit my job, half out of desperation.
Expressions
やけになるbecome desperate; give in to despair やけのやんぱちdesperation; recklessness from despair