If you are from IIT, do you feel very happy that you are in IIT? I bet you don't, at least not as much as you first got your JEE result. Similarly, even if you get such a job, you will not feel the same happiness one month after starting your job. So, don't worry about it. Happiness doesn't come by money otherwise there would be no rich person committing suicides. Moreover happiness also doesn't come by fame, beauty, talent, etc. otherwise people like Kurt Cobain and Amy Whinehouse would still be alive.
If you are not from IIT, did your life end when you did not get into IIT? I bet it didn't. Many of my schoolmates who never to IIT are earning much more than I am and (unrelated) seem quite happy. So, just try to be happy with what you have.