Minor Mix-up

When I started posting this game, I had forgotten which side I was, so I started writing comments for White when I played Black.  In hindsight, I think I understand the first half of the game much better because of that.  Maybe I should get confused about which side I'm playing more often.

17. ... Rdf8. You allow your opponent to invade with Qxa7. Your king is very lonesome with no defenders.

"21. Qxb7 I think he would have been a little better with Nxb7+, though I think things would still be pretty even." Black is down two pawns, that's not 'pretty even', that is losing.

23. ... Bg4 allowed Nxe4, which your opponent did not take advantage of. That pawn on e4 has been weak the whole game and has caused your bishop to suffer on f5.

26. ... Bxf1 loses a piece, although your opponent did not take advantage. If white retreats his bishop on move 28 instead of moving his knight, white has gained a piece. 

39. ... Rb6. You should look for the most active place for your rook which was 39. ... Rc8. From there you can infiltrate your opponent's position. You are lost at this point, but your only hope is to infiltrate with your rook and win back material before your opponent promotes a pawn.