Your Friend who is going to Juilliard who said “I got in, so you definitely will” was comparing apples to oranges. When you apply to a conservatory like Juilliard, there is no music supplement because your playing determines if you get in, period, music supplements are usually used as far as I know when applying to regular schools…and the “I got in, so you definitely will” doesn’t mean much, as almost everyone on here will point out, such comparisons mean very little in terms of how school will react to your playing, my son would tell you that people he knew who he thought were much better than he was didn’t get into the school/studio he is in, in large part because it is hard to tell what they are looking for…
That said, I would try and find a high level teacher to evaluate your performance, to see if your playing would in fact help with a music supplement. I doubt you are going to find teachers who will look at a recording you have done to do an evaluation like that, usually what people do is play live for a teacher and pay them for an evaluation (there are exceptions). If you are playing with adult musicians, maybe they or the head of the jazz program you are playing in can recommend someone.