Dark Matters role in the early universe

I looked everywhere and in my astronomy book but cannot seem to find what role that dark matter played in the early universe? also, why was this role important to the development of the large scale structure we have today?

As far as my knowledge goes, dark matter is photons that, during the first moments of the big bang, had so much energy that they started spinning so fast that they went into another dimension (it is much more complicated than that, but it is the gist of it). They still exist in this dimension, however we can only 'observe' them through the gravitational effects of distant galaxies.
This would mean that in the early universe, dark matter added the needed gravity to cluster atoms together, creating stars and eventually leading to the galactic structures we see today. Without that gravity, it is possible that stars would not have be created, and our universe would just be a structureless wasteland of scattered energy.

That is because no one knows.

No one even knows what dark matter is.

Dark matter were the means of consolidating gravity and changing energy into matter.