Making a huge mistake, mentally giving up, but coming back to win the game

After the loss, I suggested offering my opponent the win and playing a new game.  After a few moves I saw what I interpretted as weak, conservative play.  I decided to play on, and see how long I could survive.  If nothing else, I would learn how to play with a disadvantage and hopefully grow as a player.  Deep into the endgame, a series of plays by White looking to take pieces rather than set up checkmate allows me time to promote a pawn.  That promotion proved fatal to White. 

This is a game between two new players.  Neither of us have studied chess long, so please be gentlemenly with your criticism.  We both learned from the game.  I learned not to resign too quickly.  He learned aggressive play by a weaker opponent can negate the numerical advantage.  We've both gone on to play more games together, and formed a friendship here on the board.  Thanks for the forum fellas.