Some of these answers may seem flippant, and I apologise if they do. Many of the concepts I do not even pretend to understand. I do not comment, I merely report...

You are using the un-proven and currently un-provable belief that the black hole is infinitely massive, that inside you move at a tremendous speed and that it only has a middle, to dispute my point. Nobody knows whether time is distorted in a black hole. It can be just as easily assumed that it ticks at 1 second per second like everywhere else in the universe.

You are absolutely correct. None of this can be proved. It is simply the best current explanation we have, However, working on the assumption that Einstein was right...

Nothing can travel faster than the speed of light.
As things travel faster, they become more massive.
If light can not escape a black hole, which is what the maths suggests and what we appear to be observing in the universe, then even something which is not moving at the even horizon, will be moving at the speed of light when it gets to the middle.
Anything moving at the speed of light is infinitely massive.
However, the black hole itself is not infinitely massive because...
Space and time are distorted by the black hole (and indeed by any object)
At the singularity, space-time is infinitely small, and stuff is infinitely big, hence there is infinite density.
Because of this, although there is another side to the black hole, there is not necessarily another end. All we can say is there is a big happy oneness in the middle, through which nothing passes.
Although space-time are distorted, if you exist in that space-time, time will continue to tick away at 1s/s. Only to an external observer will time appear different.

If you’re in the middle of the St Hypolite tunnel you are most assuredly beneath the St. Lawrence river between Montreal and Longueuil, no ifs, ands, or buts about it. If you are from out of town, we blindfold you and bring you to the middle of the tunnel, you might not know where you are and you can conjecture all you want, but you’ll still be beneath the St. Lawrence.

You are only beneath the St Lawrence if you are observed beneath the St Lawrence, which is a different argument altogether. Otherwise you are only probably there.

A black hole is not like a hole in the ground with an opening at one end and a closed bit at the other, nor even like a tunnel, with two openings and some space in between. It would only appear as a 2-dimensional black circle on a simple 2D image of space. It is actually a 3-dimensional entity, into which things enter and never leave. We hypothesise that these things reach the middle and then do their mystic singularity thing. If the St Hypolite tunnel became progressively smaller, such that it was impossible to pass the half-way point, then as traffic approached the middle, there would be progressively more cars, and they would be moving slower. Where the tunnel analogy falls down is that the cars would be able to keep coming forever, yet none would ever get through, and there would be no road rage.