You transposed into a carlsbad structure but you didn't play the move 3...d5 which was critical. After 3...g6 4.e4 White is simply better. I guess White was also playing the opening name game and just played "system moves." This can be a bad thing to do. White seemed to avoid the move e4 when there was no reason not to play it.
Why not 5...d5? If White plays 6.Bd3 then you can play 6...Ne7 which allows you to trade off the light-squared bishops which is good for Black. 5...b6 6.Nc3 is annoying because White is threatening 7.Nb5.
18...Qxe2. Black is cramped anyway. Otherwise White can capture on e8.
36...h6 I don't understand. Black is a piece up and White's king is done because the rook on e8 cuts it off. So it's like R+p v R+N+2p. There's no way White can defend this. Something like 36...Re2 or 36...b5 looks normal to me. Just win the game. White's rook isn't going to do anything on it's own.
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