Wow, you are on an excellent path for your main theme. Lovecraft wrote about the insignificance of humanity in the scale of the universe; you take it a step further, about the insignificance of the universe in the scale of multi-verses!!
It reminds me a lot of a quote you might be familiar with: Any sufficiently advanced technology is indistinguishable from magic. And, in this case, the magic is dark and eldritch! I love the concept, and the blending of Science -- as long as it does not become a sci-fi thriller ;)