I’m sorry that you are feeling this way. Seems from your other posts that you are experiencing a lot of anxiety about many different things.
In terms of your GC, the fact that you go to a school with such an active and involved counseling department means that they are knowledgeable about the process. Remember, your GC sees the bigger picture from the applicants from your school. They know who is applying where. My D’s GC also steered students in one direction or another because they have a more complete picture of the competition from the school. From your other posts where you included stats, I think your GC was spot on and you should be rejoicing about your Cornell acceptance, not second guessing.
Go get some Cornell swag and join the accepted students pages on social media.
Celebrate that you are going to one of the best schools in the country.
Go Big Red!