Best you found out about this sooner rather than later. You must know it would be found at some point.
You do not say anything about ‘emotional distress’ that is really low and will harden them against you for such tactics. That is a term of law for lawsuits so it could sound like you want to sue them. If you have emotional distress them you need to show diagnosis and treatment.
Only say that you had planned to attend when you received the award and let them know it is your first choice and take the advice above. Hurry get an email in asap.
You have to understand that probably they don’t get to report you as new NMF because it has to be for rising HS seniors so it doesn’t help them brag how many to US News. So many they will be kind enough to come up with some replacement award for you. I don’t think there is anything technical.