I don't know. You were certainly stonewalled.
Just an impression I had was that black made too many time-consuming moves. The whole business of moving the King to allow the Bishop on c8 to go to g8 just didn't feel right to me. Maybe if it had been exercised with threats or something.... I thought, when I saw it, that 12...a5 was a mistake, as was letting your Queen face down that Rook on d1. An attack on the flank (white's attack on the Queenside) should be answered with an attack in the center.
I have just a little experience with the dutch defense. A couple years ago I played in a thematic tournament at GK where everyone had to play the opening moves 1 d4 f5, and I learned that Black's plan is not to be underestimated. I'm not much of a fan of the stonewall, but somehow fell into it here. My play felt strong through the first half of the game, and then I got totally lost. Your help at figuring out the right plan is appreciated...