Realize that you have options. There are places even here in the US where people don't have the option of being out of survival mode enough to ponder these issues.
If I were you, this is what I’d do: I’d pack a backpack and start traveling for up to a year.
The beauty of traveling is that, with little effort, it will take you out of your head - new currencies, new foods, new accents and people so you HAVE to pay more attention to everyday things.
Whether abroad or in the US, I’d suggest you do some volunteer work. When you don’t know what to do for yourself, go do something for another person (or for animals, the environment, etc…).
Besides traveling and volunteering, something else that’s great for when you don’t give a hoot is to read.
Read just for reading sake! Not to make you a better person, to get ahead, to pass the time, to be productive. Just find anything or anyone that interests you and read about it.
Remember you are not the one feeling this sense of helplessness.
It's ok to fail. I know how bad you feel now. You worked so hard to get into your dream school and you didn't get admitted in the end. It just didn't make any sense. Just let all these emotions out. Cry it out. And let it go.
You are not alone. There are people around you who cares about you. Your parents, friends, siblings. They were always there. Go talk to them and tell them how you feel.
Life is meaningful. Stop whatever you are doing and think about your life. What is important to you? What makes you happy? Or what makes you particularly sad? These are a few places you can start.
Life's beautiful. It may seem like life’s unfair because you didn't get you wanted after giving up so much. But these failures and setbacks will renew your perspective in life. You realise you didn't really need whatever you're working so hard for. You start to cherish the people and the things around you. Endure the darkness because it shows you the stars.