I don't buy it.

The world is on a loop but not a Nuclear War loop. We go through periods where the planet gets warmer and warmer, before it cools down and goes into an ice age. We're currently getting warmer and with the pollution in the air, making the warming speed up, it is actually delaying the next period of cooling for the planet which it requires to refresh itself, so the next ice age would've been some time within the next 50,000-70,000 years if you use pre-historic research but with the Co2 in the air, it's made it more difficult for the earth to cool which is seeing predictions and data surrounding the next ice age read that it's likely to be around 100,000 years plus till the next one. But the earth is begining to see the Co2 levels reduce with more environmentaly friendly technology coming out so that may assist in ensuring the next ice age isn't as far away as expected, still way past our life time so it's pretty much irrelevant to us but it's quite alarming that one species could cause such a catastophic disturbance in the cycle of a planet.

I dont think were in a cycle because the dinosaurs were here a million years ago and i dont think they will ever be back. Just like if human existence gets wiped out i dont think we'll ever be back

This must be the first cycle in this loop then because two people can't proliferate the human species.
It takes a minimum of 500 subjects in a species for it to survive because of problems with inbreeding.

I think the much more logically palatable concept is that because over an infinite amount of time and with an infinite amount of matter - the multiverse, big crunch theory, etc. - all possibilities must come to fruition, over and over again.

Your existence is a possibility which means that it will happen over and over again but only in exactly the same way that you exist now.
If even one atom in your brain is different it will not be you.

It may be billions or trillions of years until reality comes back around to forming in exactly the same way as it has now, when you are born and live your life.

According to this theory, you cannot change any decisions you have made, you won't even know you have lived before.
This is not the first time I have wrote this and this is not the first time you have read this.

I might be crazy, but this makes complete sense to me, it's probably the most sobering belief I hold about life.

Well, you can say that after a massive disaster, only few are left to create a new society
But what happens when nobody is left? Will evolution re-do itself, or was evolution a fluke after all?

The earth is flat.

If our world is on constant repeat, or a loop like you said, how come historians and architects don't find evidence of this? Are you implying that civilizations repeat themselves? That they just start over after they are destroyed? That's not a conspiracy, that's a historical fact. Take the Roman Empire for example. It fell, but it rebuilt. Humanity will one day be completely irradiated and destroyed. The end cause is still up for questioning, but I think that once it ends, there won't be anything after that.

Our planet can't stay forever. Even with the idea of a "loop". Our planet would run out of resources and no longer be livable.

I've seen a video on Terence Mckenna saying that the world repeats events. Now your loop theory could be in the same bus as his. I wouldn't doubt it. Also the loop theory could also tie in with the universe being simulated and the loops could be different simulations being programmed into the universe. But I'm just reaching with my imagination.