The idea you're getting at is that by somehow "stepping outside" of the universe "as we know it" you'd be able to determine what is "real". Whether that's you waking up in some other reality, being unplugged from the matrix...it doesn't really matter. The concept would still remain, you'd eventually find yourself asking if that existence some kind of illusion/dream etc. Even if you knew 100% that this was just an illusion, you'd still be left with "well, what now?"

Say you float out past the furthest star in the universe. You keep drifting out and look back and all you see is a small white point of light. In that white point of light is the entire physical universe, yet there you are... In a sense, you've increased the size of the physical universe by simply being where you are in relation to the rest of it. Existence simply is. Your concept of what it is has no bearing on what it actually is.

Point is...while it's all interesting to think about, nothing good can come from letting such thoughts effect your life.