Nuclear reactions convert mass to energy, they don’t create energy out of nothing.
Precisely as Cripplecreek suggested, energy and mass are interchangeable, but niether can be created from nothing.
Sort of.
Subatomic paricles are “theoretically” spontaneously pop into and out of existence all the time. This is the scientific community’s theory-du-jour on why the speed of light may be variable, and ultimately the basis for Hawking’s assertion that there need be no God for a “big bang” to happen.
To me, it’s a matter of perspective. You can look at the universe as the creator of God, I suppose (by proxy of human invention.) Or you can look at God as the creator of the universe.
So many things had to be exactly right for the universe to create US, however, that for me the question sort of answers itself. :)
To answer your question in short, however - No, being unable to create from nothing does not prove the existence of God scientifically. Physicists would love to fricasee your brain trying to grasp quantum physics or another exotic explanation for genesis.
I prefer to apply Occam’s Razor here and submit that upon examination of the scientific community’s best theories on the origins of time, space, matter, and energy - I think their dogma takes more of a leap of faith than picking the deity of your choice to credit creation to.