Finding One’s Ultimate Calling

I have been trying to find the ultimate calling of my life. I am finding it hard to specifically point the one thing that I would excel and have the passion for so that my work becomes my play. The course of my life has been such that any passionate and deep longing and wish that I recognize, materializes with time. I am just lost with wanting to know what is that I can do now, to make the world a better place and also enjoy doing it.
I hope to answer these prime questions to realize my super-life with some help from you.

For some background info: I am 29y and from an well-to-so middle class family. I had a daughter 2 years back. I am usually liked by most who know me. I bring energy, optimism and life with my presence.
Marriage is something that I am still learning, was married early at 21y to a person I love. But, with my convictions and discipline, problems do stem up with day to day happenings. I am working towards understanding myself and the others better.