Something happened...
I was playing on the new mode and what I think happened is I got hit against the celling hard by a bouncer (and might have died at the same time) and glitched back far enough to get here, but idk.
Oh no! I'm sorry that happened. You're not supposed to be able to get here unless a very specific set of circumstances are true, and it appears you got here by accident/through some unintentional bug. Because of that, there's no intentional way to get out either.
You will probably have to start a new game if recalling your last checkpoint is taking you here.