The long and short of it is I should never have been sent there in the first place.
I've worked with mental kids in huge mainstream schools, Middle Eastern schools with nothing but Arab speaking kids, special schools of varying degrees and even the odd stint in schools for kids with behavioural issues (i.e. jail lite) and always got my head down and got on with it but this was beyond anything I could deal with.
Apart from the fact it was a primary special school, these kids need a carer not a teacher - no mobility except for random spasms, no communication except for the odd cry or whine, not sure whether they actually comprehend anything or not.
I told the support assistants I'd been working with hat I had handed in my notice and they said the class (now lets be fair, there's a school full of people actually qualified to do that sort of thing... why are none of them taking that class?,...) has had a long line of teachers who come in and about turn. The guy before me was a high school french teacher from Poland who could barely speak English.
I.e. the powers that be just want someone, and quite literally anyone, with a teaching qualification to be stood in that class so they can tick a box and say these kids are getting an education.
Apart from that there's been alll sorts of stress and anxiety related symptoms kicking in and my health is more important than any job or financial recompense.