[Serious] Is the Past Real?

[Neo-Scholastic]

Here is my secular argument:

There is nothing outside actual physical reality.
Physical reality keeps overwriting itself in the present like a claymation model.
Since actual physical reality is everthing there is no independent remaining record of what actually was remains.
As such, there really is not  a definite way things were.
The garden of forking pathes opens in both directions. Possible futures spread before us. At the same time, the number of possible pathes leading to now also expand.

What about numbers?

The question of mathematical realism seems independent of one's time theory. Even in presentism there is still the idea of conditions that must always present in all possible worlds. Perhaps numbers fall into that category of being even under presentism. Or maybe I am moderating the presentist position.