But due to Brexit, I need all legal papers now, as I need proof of address and living here, or they'll ship me back (not that I love it here or anything like that...)
So if I quit today, I would still need that contract eventually to keep things legal.

It's just all kinds of wrong. And getting ready to go now. Been up for the past 2 hours, with pains in places to make me have a panic attack, but I'm sure it's just pure stress again.