i liked it up until move 20. that was ok 0-0.21, .erm b-h4 ..or knxkn... or dunno but im thinkin of re1 at some point before the epawn is taken ? 

My thinking here was like this : if I move Bg5-h4, black could easily reply with pawn g6-g5, attacking my Bishop which I needed to block the black  horse on its square before its king.

Moving Rook f1-e1 I would have given my black Bishop to black  and in the following moves, also my white coloured Bishop. So what I wanted basically was to save my Bishop on g5 and take the black Queen.

Now I see I did not look at all possibilities, cause I did not calculate R e1.  Still learning . huh :p

Thanks for the post. It really really means a lot to me. 

bxg8 wins a piece but your defense will be less

There's also 20 Nxd6 Rxd6 21 Bxf6+ Kxf6 22 Qd4+ (or 21 Qxb7+ Kd8 22 Bxf6+ Rxf6 23 Bc6+).