thanks for sharing, interesting stuff. you're a braver man than i am
I have friends who survive on playing music in London, the overwhelming thing they have in common is that they juggle a LOT of different income streams - function bands, pub covers bands (O'Neills!), session work, teaching, and in most cases some kind of non-playing freelance work.
a couple of them even have paid gigs with originals bands... however in both cases these are "name" artists and it is the exception not the rule. even these gigs don't pay much.
there are a number of function bands in the area, if you have gear and transport you might be able to get some "dep" slots with existing bands. (i'm sure you know this already, but just in case.)
... anyway, good luck!