Based on what you wrote you have 78k of equity in the house
I understand that the rent on your current apartment is $1250. Even if you say you forgot to add in the mortgage on the second home as an expense, it is highly unlikely that Cornell will reverse it’s decision in denying your appeal. They just are not going to give you additional aid because you have the expense of a second home
While it will be very disappointing, you will have to turn down the Ed admissions. Hopefully you have some affordable RD options.