What do you think of this move 18 for white. My goal was to trade the knight and a pawn for a rook and a pawn and gain momentum on the queen side where my attack was. After I made this move my opponent fell apart though so I didn't get to play the position the way I would have liked.
http://en.lichess.org/88FE9Dqw/white#35
http://en.lichess.org/88FE9Dqw/white#35