I played a game (black) with zero mistakes & blunders and still got absolutely crushed

After the game ended and before I checked the analysis, I already felt that I didn't play poorly (on my level at least). Have I got the opening idea wrong for this system? Maybe I should just wait to see what attacking ideas white has?

A game with zero mistakes and blunders and you still got crushed...I see.

12...Qc7 is dubious. Better 12...cxd4 right away and after 13 exd4 Rc8. The queen is not useful at c7.
so is 13...cxd4. With the queen on c7 it makes more sense to push 13...d5
15...d5 aggravates matters: you give him the protected passed pawn that wins the game.

I analysed every single one of his games and all I can say is all hail super GM Stockfish.

... You got 7 inaccuracies

Sacrifice bishop to early leaving line e,f,g,h in king zone defenseless

You had 7 inaccuracies which is why you lost.

@ThomasKOP

Statistic is now useless. It shows relative, not absolute blunders, mistakes and incorrectness.

Read this thread for more details, starting from:
lichess.org/forum/general-chess-discussion/wth-is-this#9

Let's see.
Very good knowledge of the opening book, both of you 12 moves!
But then your opponent plays with 3000 ELO. He is either the next world champion or a cheater.
REPORT HIM!

@pointlesswindows

This is hardly 3000 ELO game of white. The black blunders way too much and all was quite easy for white. Continued pressure, several cheap pins, several left pieces...