why time travel, the way you perceive it, is not going to be possible
Follow the train of thought, and get off the train at whatever station you want.
Matter IS NOT being made. All matter that we have is the same matter that has existed since the Beginning (whenever that was). Matter is being converted to energy (sun, stars). Matter changes from one form to another - solid, liquid, gas, supercooled gas, plasma, but the basic amount of matter is the same. Agreed?
At the very basic level, time travel assumes that the SAME matter has to be in TWO places at the same time. Example - if I were to be transported back in time to 1981, then the same molecules that have been part of my body since birth, e.g., those that make the lens of my eyes, which haven't changed, will have to be present in two places at the SAME time. How is that possible? That is only possible if we are able to duplicate matter in the exact same way. That seems impossible. (Anti-matter is a different matter, literally, I don't know much about that). Hence, because we can't duplicate matter, we can't time travel.
Dilation and contraction of time is possible, because gravity warps the space-time dimension. Stronger the gravity, quicker the time. Lesser the gravity, slower the time. It is because space-time is BENT by gravity - but time doesn't move backwards.
What about the singularity of a Black Hole? Since we don't know about the interior of the black hole, but we know that gravity is almost infinite inside a black hole and light does not escape, it can be assumed that time does not move inside a black hole. But we know black holes exist, and we know black holes collapse on themselves when they consume all energy that is left - and hence, rejoin the space-time dimension as a more 'normal' element, we can say time slows, but does not definitely, reverse.
I can say all of the above in GREEK. Or Latin, if you'd like.