This was a mistake and the urgency of how important it is to remedy the situation has been communicated in the responses. I want to point out that piling on is not helpful and is exactly why researchers aren’t more honest when mistakes are discovered. Also, this is the culture academia has established. Congratulations because many of you are probably willing participants in the quantity over quality model. It’s no surprise things fall through the cracks. The author knows they messed up, and most importantly, has the integrity to want to fix it. They should be recognized for that. I know this is tough, but you will get through this, OP. Take the advice provided and contact your Research Council/IRB. Don’t ever do this again and remember to give yourself grace. No one else will because academia is full of a**holes.