trying to play with a plan !
I think that after 22. f3 that you could have opened up his kingside with 23. e4. Your position is really strong and your knight is the best piece on the board. I realize that it is difficult to re-evaluate the position when you feel that attacking up the h-file is the best idea, but the f-file looks great in that position! Once you allow Black to open up the b-file and liquidate the pieces, your winning chances have ended.