Closest to hell I've ever been were the times I was asleep but also awake within a night terror that layered both reality, and literal fiery hell so I knew where I was but also didn't. My eyes were open to two realities.
Closest to multivese I've ever been is when I am 20+ layers of dreams deep and trying to wake up in each one and need to pull through every world that feels entirely real...just to finally wake up home and not feeling real until I can shake the sleep inertia.