I exist today as a configuration of cells and experiences combined together.
If you crushed an acorn did you destroy a tree? Absolutely not... you simply crushed an acorn.
you destroyed something that had the potential of becoming a tree. Not really sure why you want to separate these out into two distinct entities. What would you consider an acron that sprouted a stem and a leaf? A tree or an acron? I think most people would see that an acron is still the same living being, just a different configuration of cells in a transitionary state to becoming a tree.
You are a distinct collection of cells. As opposed to your neighbour, who is also a distinct collection of cells, which is different from you. Every one of your cells is different than his cells, for one, because they all have different DNA than your cell's DNA.
Its fine to claim that you only exist in the present moment. But to deny that your past self also existed for you to exist now, seems a little discontinuous and meta physical.
Also at what time scale does your past self not exist. Since your perceptions are time delayed. You might stub your toe, but it will take a split second for your brain to notice.
They are two distinct entities: the acorn in front of you actually exists as a collection of cells. The tree does not. The tree is an abstraction... a myth in your mind. It does not have any true physical properties.
Every egg is not a chicken. Every sperm is not a person. It has the potential, yes, but in the present moment an egg is simply an egg.