Game finished a draw but I lost in Tournament.

I was playing in the Round of 16 in the Tournament and it was 6-6 after 162 minutes and then the game finished and I lost 5-4, has something like that happened to anyone else before?
It's rare but it's a shootout loss. I've never experienced and don't understand all aspects but I've read about before.
In case of draw game in the end of extra time, the winner is determined by penalty shootouts.