A difficult pawn endgame


I was white. I probably overestimated my position and looked for breakthroughs that weren't there. I'm interested in other peoples opinions about the starting position and about variations that might have been better for me. I'm especially interested in 11. Ke3 instead of 11. bxc4, and 15. Kc3 instead of 15. Kc5.

This looks like a trivial win for White, honestly. The passed kingside pawns are too powerful to be challenged even if completely abandoned, allowing White's king to take action on the queenside and neutralize Black's pawn majority, and then return to the kingside for an effortless win.