FWIW, I was also rejected from Olin (I applied to be in the very first class of Olin Partners, back in 2000), it was also my first choice, but I learned that if your top choice is an engineering school don't say that you want liberal arts. ;-) I ended up going to Amherst, had a decent-but-not-great time there, and then had a very successful career as a software engineer, working at 2 startups, founding one, ending up at Google for 5+ years, and now founding my second. If I had to do it all over again, I might not have done liberal arts (actually, I regret not applying to big schools like Stanford, CMU, or MIT), but it turns out you can recover from most mistakes you make as a teenager. Good thing, too, because you make a lot of them.
But all in all, if you try and fail...that's life! Sad but true. You win some, you lose some. It's how you react to the losses that really counts. Pick yourself up off the floor and find something new to fight for.