New player, help me analyze my loss.

To my astonishment, I believe the position was very even at move 7. In such games where your king has been forced to move over to the d-file, there are some positional things you need to do:

Play ...f6 to protect your e5-pawn and to repress any of White's minor pieces from moving to g5.

Play ...Be6 to prevent Bc4 from threatening your f7-pawn.

Note in both cases your weak point is your f7-pawn.

I believe the rest of your problems in the game stemmed from neglect of those two positional moves.

Thanks for the help. I believe e7 might have been a better square for my knight, allowing f6 to be played. 

Thanks so much for all of that. That was really informative, and I can take a lot away from it to improve my playing. I agree that I need to start thinking simple and positional because it's apparent now that a lot of my moves made no sense. Starting by putting pieces where they're needed is a great tip; it seems so obvious now.