yeah 16.Bb5 would be a game winner. Ok you missed that tactical thing, but you could have won even so. You had a good game till blunder in the end.
I believe you could have won playing 25. Bxc6. (After 25. Bxc6, to recapture with the bishop would be a mistake by black cause of ... Bxc6 26.Rxa5 Rxa5 27. Nxa5 and black’s bishop is lost.)
Here's the best line, I think: ...Rxc6 26. Rxc6 Bxc6 27. Rxa5!
And white would reach a Knight vs Bishop endgame being up a pawn.
Your knight would stronger than Black's bishop, cause of the pawns structure. In K vs B endgames, it's usually better to have a bishop when pawns are in both sides of the board, cause it's a long distance operator. On the other hand, Knights can attack all squares, not just one color like Bishops.
Considering your pawns are on dark squares, weakening black's bishop, and considering pawns are concentrated on one side, in this case white's knight is stronger than black's bishop. And, of course, white would be up a pawn.