Please dont kill anybody
Nope, that's not how science or "destiny" works. Your Future is in your hands, not destiny's.
It's more of an alternate take on destiny and if you are arguing multiply realities for the science standpoint they are alternate version of "You" and not "you yourself" (You don't share a consciousness) so "you" who is reading this do only live one reality. Destiny is also a concept so it is up to interpretation and doesn't "work" in any specific way.
you're choosing your choices and action though and your actions can affect the future so technically there could be a different future if you didn't do that action.