Never Give Up
As Matzleeach said, you should have castled before 9. BxPg7 overwise the rook can take g2 after scaring off the bishop and you won't be able to castle KingSide anymore.
Just try and make sure everything is protected. Castling is often a very good move to not only protect the king, but also to add some protection to your side pawns after the minor pieces have moved off.
You played some good moves in that though, well done.
I would like some of you to look at this game. I ended up losing a lot in the middle of the game on one mistake. However (lesson to the beginners), I did not give up and continued to make moves. I ended up winning this game.
What mistakes would you have changed and what would you have improved upon? Thanks.