Thank you for your comment.
Maybe I did not fully consider the consequences of b4 but I was trying to get my knight in a position to protect the pawn if he were to exchange the pawns. It seems that this is the move that lost me the game.
I then realised that the advanced pawn was lost anyway because sooner or later he would bring his king to attack the pawn as well as his rook, and there would be no easy way for me to defend it again.
Hello
I played black in this game and would like to know where I went wrong or what could I have done better. Any comments would be much appreciated.