I'd been getting pretty fed up with driving every morning, you know.
Literal
Every-morning driving do [about-のに] considerably fed-up had-been-becoming [feminine-のよ].
うんざりしてきていた layers three auxiliaries: ~して (doing) + ~てきて (gradually becoming, change over time) + ~いた (past continuous). The result is 'had been gradually becoming fed up.' のよ is a feminine sentence-ending particle adding a confiding tone.