Nah, this universe is 3d.

I'm assuming you are thinking that time is the 4th dimension and we have time here so we are 4d?

Time may be the 4th dimension, but in our universe, time doesn't actually behave like a proper dimension. For one thing, dimensions should be spatially perpendicular to each other and time is not. We also seem to only be able to move one way through time whereas we can move back and forth through the other 3 dimensions.

Dimensions get weird and complicated. For the intents and purposes of this conversation it's correct to say that the universe were experiencing now is 3 dimensional.

Three spacial dimensions, which is normally what people mean when they say that, unless they specify otherwise. For example, we call them 3D game engines, not 4D. Yes, there's also a time dimension that is special. It cannot be moved through freely.

Yes, but if you're beyond the event horizon of a black hole time becomes basically* irrelevant. You could literally turn around, look back out towards the rest of he universe, and watch all of time play out in the blink of an eye.

You know that scene in Interstellar where they land on the planet for 5 minutes, but 20 years passes for everyone else due to the planet's mass? It's the same thing, but a billion-billion-billion times more severe.

Do you have any idea how little that narrows things down?