OP means the Original Poster; that would be you.
What I was saying was that since you're 1400 in tactics and endgame, but only 1200 in the opening, that you shouldn't resign just because you hang a piece in the opening against an equally-rated opponent. Your pieces are worth more in the middlegame and endgame than theirs and you should have a great opportunity to win back the lost piece, or even win the game.
Your pieces are worth less in the opening, just as your pawns are worth more in the endgame.
the ebst way to learn an opening is to study the endgames that arise from it.
@zBorris. Yeah, you r right. Look at this:
To avoid loosing material in the opening, just follow the traditional principles: move few pawns, and only in the center (if posible). Develop the knights and then the bishops, castle and comunicate rooks. If you do that you should be OK against any type of opening. And don´t move the same pice twice (unless they are attacked by a pawn)
In this game you are posting, you move your knight twice (g1-f3-g5) without castle, with many pieces undeveloped and so on. This is a common mistake, trying to attack without weapons, not a good idea as black showed to you. Just play 0-0, d3, Nc3, Bg5 and you´ll be in the main italian game and play from there.