You are quite right we and all you see started with the big bang and some of the matter condensed into stars. By their nature heavey elements were made this soup this is then made available when the star explodes as billions have done in the past along with any planetry sysytems that they may have had,,,,,again and again...true recycling.
So yes, matter can not be destroyed or created.. what we have now is what came at the big bang just the elements have been changed around and that is what we are made of...Star dust!
Cheers
John