what was my mistake?

- u took the bishop the wrong way on move 18
- u shud have takenknight on move 6
- your bishop is hanging on move 11
- dont be so passive u didnt make a solid thert the whole game
- seemed as if your opponet was very weak just play more u can clober this guy
- hope i helped
Yes shoud have taken the bishop with the queen not the rook to avoid the pin and try to force the exchange of material after being up a piece.
also could have gone a pawn up a couple times in the opening.

before you move a piece...
look at the whole board
- for free pieces.....
- for your pieces that are free for your opponent to pick...
- once no free pieces can be captured, think of a plan.. i.e. what can I attack easily ,etc...
then play loads.. good luck.
18. ... 0-0 wouldn't give black the upperhand by taking the bishop.
If black played 18. ... Qxd5 then 19. Re1+ could pose a problem unless black plays correctly. Seeing that black wanted to play Ne7 suggests that black would have some difficulty.

thanks but I think your line was probably the best and easiest to understand. I guess the main point is he had three options to keep the game in his favor. I hope we did not confuse the guy to death.