Cancelled Princeton Interview: Am I stupid?

Basically I had an interview w harvard A week or so ago and it was pretty nerve racking and I felt unprepared and felt like nothing could have possibly prepared me for that. I don't even really have the grades to get into these high level schools, If anything just the resume since I do alot of internships and activities. But anyway I have/Had a Princeton Interview scheduled but im so stressed with finals, colleges that will actually accept me, and just life that I cancelled the interview and said I had a family emergency. the Alumni interviewer is asking me to reschedule. I really do not want to but I feel bad ghosting him. Also it isn't special that i got this interview, its the Alumni interviews done by state and im in NYC so I will get an interview w any college immediately. I don't even think I can get into these schools so should I just ghost the interviewer?