Sentence:  He sounded quite excited, as if he were deriving some vicarious pleasure from the anticipated outcome of my efforts, and I hadn't the heart to tell him how, at that precise moment, I was feeling quite ready to <WSD>chuck up</WSD> the whole thing. 
Meaning of the word marked with <WSD> tags:  To (chuck up the sponge); to give up; to admit defeat; to break a contract; to abandon or quit (something).