Blundered checkmate in 4 moves

I failed this puzzle because I thought the queen sacrifice was too good to be true. But i should've realised queen sacrifice was indeed the way because f8 f7 escape squares hinder checkmate. But queen sacrifice is not the only gambit, the pawn promotion is also being sacrificed too. Furthermore, i thought there may be discovered check leading to pawn promotion; but then there's no way to hold on to the promoted pawn. I should've trusted my gut instinct Qd8+ KxQd8, c7+ Kxc7, Nd5+ Kd8, Bb6#