Hello.Also, Girder of Loins give the "backward infinite theory" that has many apparent flaws. First, matter does not necessarily have a definite place. Matter is composed of very tiny particles (atoms), and so the Heisenberg Uncertainty Principle applies, which says that it's impossible to know both the velocity (direction and speed) and position of a particle, and so we can't know the exact place of matter at a given time. Though, just because we can't know it, doesn't mean that it doesn't have a definite position.
Second, matter can be created and destroyed. Energy cannot be created or destroyed (at least, for the purpose of this), and matter can be converted into energy (e=mc^2). This means that matter may not have always existed, at the beginning of the universe (if you believe the Big Bang Theory), then a bunch of energy may have turned into matter. Also, according to the BBT, time didn't exist before the Big Bang, so infinity is avoided. Furthermore, the laws of thermodynamics don't prevent the spontaneous production of matter (again, e=mc^2, but energy to matter this time). All it takes is for the universe is to become more disorderly in some other way, assuming you were talking about the 2nd law.
As for the laws of physics breaking down as you go backwards, that is true, in a way. The laws as we know them didn't exist for the first fraction of a second of the universe (again, BBT). After that, they pretty much stayed the same until the present.
Finally, about scientific laws, just to clarify, they only describe what happens, but do not propose a mechanism. And about the CS Lewis quote, even if something like your brain wasn't designed by something to think, it still could serve that purpose. For example, if God didn't exist, hands would still clearly serve their purpose of grasping things.
If anything needs more description, just say so.