So the feeling in your head is likely a vertigo attack from lying down too long. I get them all the time and they feel exactly as you described.

As far as knowing what is beyond the universe, if there are more than one, how it happened or the purpose no one can tell you.

We have speculations for how the universe started, with the Big Bang. Basically matter came together and exploded outwards.

Matter then collected together to form galaxies stars planets etc. there are experiments done on the ISS using coffee grounds that show how matter will collect together in zero (or micro) gravity that simulates planets forming.