You're right. In fact a time loop has the same something from nothing problem any other theory has.

Imagine a flatlander universe. Package up time in another dimension and you can represent their entire existence as a static 3d cube. Timeloops would just be a static torus in the cube.

The same is true of a 3 spatial dimension + 1 time dimension universe. You can view it as a static 4d tesseract. Timeloops are just a 4-taurus. Where did that 4 Taurus come from? It's the same something from nothing problem.

It's something we learn very early in the philosophy of science, is that our vision of the world will always be inherently limited by the capabilities of our perception and the way we process it

with time loops. It began half way though me writing this sentence — that's the thing

There are only two alternatives for the origin of the universe: Either creation out of nothing, or no creation through eternal existence.

Both are hard to wrap your head around.

That's the thing about time-loops; you don't need to have a start and a beginning. There's a good movie about that concept; Interstellar.

It's a metaphysical assumption, meaning beyond the realm of experimental science. Science has inherent limitations, and cannot be used to explain everything. This is a good starting point: https://www.youtube.com/watch?v=If3cNUixEBM