You got to blame yourself at some point. It sucks, but what about all the other half-white/half-asian kids that got in above you. Shouldn't you be 'better' than them too? I'm saying this because when I was in a similar (but different) situation my first thought was "wow I'm just as indistinguishable as everyone else like me....". I remember talking with my dad at this similar (but different) point in my life and he rather-unsympathetically said "looks like you'll have to make other plans". Now, and at the time, I see why he did this: to convince me that it wasn't a big deal, life goes on and you'll just have to find a way to make whatever "it" is work.
The real problem is that with anyone with a brain and time could do what you did (unless the extracurriculars are really unique). You have to actually distinguish yourself somehow, and do something that not everyone can do. I don't know what this is, and it is hard to know in HS, but I feel like this is the only way someone can know that they are a sure shot at one of these fancy places.
An Ivy-league undergrad I know is one of the very rare few to get a full academic ride to an Ivy (and he's not a minority or low-income). How? He worked in research labs for a few summers in HS, -- and spent all of his free time in the library reading math textbooks, -- and took (real) college courses where he could, -- and tried to read Ezra Pound's Chinese, -- and worked as an EMT. Just gives off the impression of someone who will excel at anything. All the other undergrads are less impressive than this, but this would be an example of someone who is a sure shot.
A cope that I took is "there's always grad school": it's much easier, in some ways, to get into a top grad school than it is to get in top undergrad, and this is where you'll wind up getting a lot of the "training" on what you'll be doing for the rest of your life. Not the same experience by any means, but not going to one of these schools does not mean that you are doomed to mediocrity. Not having the pedigree of a fancy undergrad might put a "chip on your shoulder"...
I respect the unweighted 4.0 though