I need all my time to prepare, so I'm not going to say much, or enter any of the variations. I'll edit this post tomorrow to include more. For now here it is; mission accomplished!
Edit: A little background on this game. Looking at his games in the database the day before, I was dismayed to find that I had been paired with an *extremely* solid grandmaster. Out of the 120 games in my database he had played with black in the last 3 years, he had only lost 6 games. With black! Including many games against strong gms! I couldn't believe it. I was also dismayed to see that he played 5 different defenses to e4; too many to study! But I tend to think that anyone can be beaten. So I just decided to play the most insane line I could think of in whatever opening he played against me, to try to rattle him out of his solidity. Inwardly, I prayed for the king's gambit, and spent a couple hours going over lines that have worried me in the past. This did not include the line that happened in the game, but I was still very happy from the moment he played e5.
Edit: Annotations now added. If you want to get some insights into the opening piece sacrifice, hopefully they will help you to understand it.