At this point I took some advice from Jonathan Rowson's book, Chess for Zebras, and told myself a draw from this position would essentially be as good as win. My opponent unexpectedly gave me some hope by bringing his king to c3 to try to play c5. With his king slightly out of the center. In the position below, I was able to gain activity by 42... h4! 43. g4 g5.
White had to sacrifice a pawn (he played 44. e5!?) or let my king reach e5 and my pieces target the h3 pawn. For the first time all game, I had some counterplay. The game reached 84 moves, lasted well over five hours, and I eventually held the draw!