Oh my god, I did the same thing once with cherry coke when they had weird labels! I was so crushed, lol. I know it's really a small blip of calories in the long term, but making the effort to do well and to be DECEIVED (yes I will be dramatic okay
) frustrated me so badly I wanted to cry. I was counting carbs, too, so I suddenly regained a bunch of water weight. It was a real 'kick you when you're down' kind of situation.
But look on the bright side, you figured this out quickly so it didn't go on for days or weeks (or months!). What could have been a big problem was a much smaller problem. Stay strong!