At barely over 1200, my humble opinions are quite humble ...
In short, I would suggest that you were focused so much on offense, you forgot about defense; focused so much on what you could do to your opponent that you forgot to consider what your opponent could do to you.
I do it all the time ...
I just played this game and although I'm extremely tired from work and lack of sleep - it's not an excuse. I somehow managed to blow this endgame and throw away a game I should have won.
I'm doing some analysis of it right now but I would appreciate any feedback you can give me on how I should have played this differently.
My perspective: A player with 0 USCF games played yet (changing soon) and less than a full year of experience online.
The time controls were 30/0.
Thanks