No. What you're talking about is true, in a sense. It's true that on an atomic level, we are similar, and atoms are recycled. That whole "your water might be pee" thing is kind of true. Some of those hydrogen atoms may once have been part of the atomic structure of your urine, yes. But they aren't anymore.
It's energy that can't be created/destroyed, not mass. Hell, mass is created or destroyed all the time, The Big Bang is a great example.
Again, yes some of the atoms that make up the human body are also involved, if structured differently, in making up a star, or planet or what have you. But that really doesn't mean anything.