Congratulations on fairing so well. I would have likely tucked my tail and ran/gotten nervous and left something hanging very early on.
I don't mean this as criticism of any way, but I think I'm missing something obvious. On move 25, why did white leave his queen hanging on the e file and play Rxc3 instead? Wouldn't this give white a queen and two rooks in the end game versus blacks two rooks and the knight?
I played this game today as part of a tournament, I was originally pretty intimidated by his 1720 rating (nearly 400 pts above my own) but I managed to get a 1 pt lead in the endgame with 2 pawns up and a queen vs 2 rooks.
I was afraid he would still beat me though so I decided to force a draw by repetition/offer a draw.
Here is the game, any constructive criticism is always welcome thanks in advance.
http://www.chess.com/echess/game.html?id=13247219