welcome to chess man
game analysis
Hmm. Okay, why did you do b4? You should have just moved your king to the side. The b-pawn was protecting from the king to take advantage of the queenside (, maybe the kingside later) and that counted as a blunder because the King could take advantage of the board. One word, zukswang. You are right. 36.5 moves of perfection and a draw position, and then...no advantage of anything and give up..
https://www.chess.com/a/2ghppvesx21iP8
36 moves of perfection, then...dead. Sigh.