You searched for an attack when you should have been defending. You started defending when you should have been attacking. This seems to be one of the most common flaws in my Chess thinking ... becoming passive when I should be active and being active when I should have held strong.
My opponent also made the same mistakes. We both missed them. Had I not turned on Fritz after my own analysis they would have laid dormant. Above all, it highlighted over optimism on my part after returning to an equal position from a winning position ... a common psychological flaw.
Distressing was finding out after the game that my opponent had 3 chances at making decisive blows which cause me to instantly resign.
Firstly, I'm White in a Dutch Defence opening, and was very satisfied with my opening position where my opponent missed a pin by making a natural move. My opponent (rates 2000+) appears to have let many games go on time to plummet his rating in what was a drawn ending.
Removing the Guard
My opponent has just played 10. ... Nc7. It has hard to believe that despite the d5 pawn being defended by 4 Black pieces, by force White removes all the guards of d5 to obtain clear advantage.
Playing on general principles
A big Chess flaw I have is playing moves on general principle instead of concrete analysis. Here I instantly discarded any capture on the c-file, for not wanting to expose my King. But yet, Black can't take advantage of the c-file. Instead, "secured" by Bishop with d5 failing to see half a move ahead the simple idea of harassing my Queen.
Easier to Attack than Defend
A typical error of mine to be active when I should be solid. 27. Qh4 is a very difficult move to find, with the idea to organise defence with Re1
Chance One for Black
Both players missed the possibility of the decisive 28. ... Rxa3!! opening up the b-file
Chance Two for Black
Both players missed that despite Black's Bishop and Rook hanging, there are terrible threats at b2 with 29. ... Rf2!! exploiting b2 and the Rook at g1
Chance Three for Black
I pleadingly had offered the exchange of Queens with the meek 31. Qc3. Both players missed the final blow of 31. ... Rbxb2
3 File Checking Distance
This hypothetical ending was reached in analysis, and taught me much of the role of the Rook. Black can draw because of the spacing of the pawns. The Black Rook keeps the White King at bay with continual checks and always threatens the d-pawn (never allowing the a-pawn to advance).
My Game Annotations and Analysis