a cheap win? please comment on my annotations

I fully expected to lose after I found myself down two pieces. Then I saw a mate threat, and, apparently, so did my opponent who resigned. Can you please comment, esp on my annotations, so that I can learn to think more deeply about my moves, and those of my opponent. thanks. 

I got the ratings wrong. I'm somebodysson I was black,, and I'm about 1000 now on chess.com. My opponent, white, was about 845. The game is listed in my games archive. 

on 28...I mean 'since, like me, white, seeing no way of stopping my Qf1, resigns. 

I realize that the game posting guidelines say to not post wins, but since I think I played terribly in this win, and since I want to get help on my thinking about my moves, I think this game is as good as any example of how my thinking needs to improve.