It just feels like all the hard work meant nothing
Working hard is a pathway to one's goals, but not always a guarantee of achieving them. Rather, it is a measure of who you are.
There will be many times on your road of life that you''ll believe you deserve/have earned something -- a job, a promotion, a committee assignment, etc. Sometimes you will have done everything right, done all you could, and it still doesn't work out. Sometimes, it's not fair and other times, it's just not meant to be.
It's happened to me many times. I was angry, frustrated, hurt, bitter. Eventually, those feelings eased and I sorted out my other options. In almost every case, what ended up happening was (in hindsight) better for me. Either that, or I made it better b/c I was determined to do so.
The qualities that you have demonstrated will be those that drive you to success on whatever path you take. You will make whatever you choose successful because you are successful. You've already proven that and the fact that you don't get into a particular school (or don't get a particular job) doesn't change that -- unless you let it.
