You are now experiencing what Early Man felt when he started to realize the Earth Wasn't flat, or that we were not the Center of the Universe. The Early onset of this shaking of understanding often results in "Denial".
These are the things that have the greatest minds in Physics baffled, so as Brian Regan put it, "Me sitting on my couch eating a bag of Potato Chips doesn't stand a chance of understanding this".
Even the Scientific community itself has some divisions about Intellegent Design. Great Minds Like Eienstien believed in a Creator, Great Minds like Steven Hawking, believe the universe exists due to a cosmic crapshoot of coincidence.
I'd like to think of Existence as a little more than the Goldilocks Paradiem.
You Really should Start with Episode 1 Season 1 and Watch the Whole Series. In Part 3 of that Episode a Computer programmer likes to think of the world like it is a Computer simulation.
Here is Episode 1 Part 3 that Goes along the Movie "The Matrix" concept. Kinda like your idea of illusionary existence.