Citizenship help!?

I went in yesterday for my interview and passed it! I was really excited until he pulled out my application and telling me I didn't even have to file N400 because I am already a US Citizen because of biological father. Now they're asking me to file N600 instead, and I have to provide my fathers certificate to prove he is a US Citizen already and the problem that I have is I need to provide some kind evidence that I was in his custody when we moved here in the US. I don't have any records of bills anything address because I was under age at that time and we did live w/ my dad for a few months only. So before I even started highschool here in Nevada I already lived with my Aunt and Uncle so I can go to the school that I want (bcause of the zoning). Wil a notarized paper saying I lived with my dad when we moved here is enough (w/ his signature so I can be naturalized? or is there anyway I can ask DMV to give me a paper copy of my State Id (My very first ID) from 11yrs ago? What are my other options?