I got as far as 8... Bd7. 8 ... Bxf3 would have won a piece and the game for you
This guy didn't make a single wrong move

8.Qa4? (8... Bxf3) Bd7? You blundered then he blundered... so he was definitely human.
Oh *reads rooperi's note* -- yeah I got the colors reversed... okay I'm human too... but yes blunders all around.
Oh *reads Alphamarkomega's note* dammit, I had it right the first time and rooperi led me astray. Okay, I'm doubly human and blundering more than anyone.

8...Bxf3 9. Bxf3 Qxf3; he misses winning a piece
13. Nxd4 exd4; would have given you a much more comfortable position
14. a3?; for a very long time now you should have kicked the bishop with h3.
after that, he just crushed you convincingly.
16...Bxg2 is stronger, Kxg2 can be met by Qf3+ with an exposed king.

Okay, now that I've got the colors correct --
Alphamarkomega, the Qa4 blunder is forgiveable in that you were trying to accomplish something, breaking the pin on the Queen with an attempt at a threat... but the move that doesn't make sense to me is:13.Qd1 ... you'd gotten your Queen out of the pin and he gave you a break and made a not very strong move Nec6... and you plop your Queen right back at d1 instead of playing:
"13. Nxd4 exd4; would have given you a much more comfortable position" as bondiggity put it.
Try to remember what you were thinking there. Your thinking was clearly flawed and you want to understand what you were thinking and fix it. Your N was in trouble because of the pin on the queen. You wanted to exchange the N while the Queen was off d1.
I made some silly mistakes, but it's as if this guy was always 5 moves ahead of me, it was just crazy