White holes create space and matter, and Black holes took them away. Together, the two phenomena kept an equilibrium on the amount of energy that existed in a galaxy at every time.
White holes only appeared once towards the start of the universe formation when galaxies were already starting to form.
The White holes spewed out as much matter and space as they could and then went dormant. The galaxy at that moment would be in equilibrium that nothing could disturb. After that, the galaxy would go on to create billions of stars and planets.
And then, the problem would arise when the planets would start creating life, and along with them create an Origin of their own.
Now there was more energy in the Galaxy than the galaxy could possibly handle. In such conditions, the galaxy would fester until it was ripe with a lot of energy.