In the end, I didn’t succeed, never had a girlfriend, and now I’m going to die out.
This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means decay, so the verb version is to decay or to die out.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
The entire world would start to die out if there were no cookies (く) left! Can you imagine your life without cookies? The trees and animals would all die too. Because they love cookies. Not just us humans.