Prepare, but don't die. I left teaching in 2006. I went back in 2011. It has changed, but in the ways you would expect. Yes, YOU are responsible for every childs result. I was initially shocked at the amount of flak I got for failing to move on a child 3 sublevels.
But then, I got my balls back. Hang on. Not everything has changed. You get your teacher head on. I assessed my class. Overlevelled, they were. I sat them SATS. Proved, this was.
To the Pupil Progress Meeting I went. Ridiculed I was. Backed by the LEA ladies I was.
Left the school that bullied I did.
IME, huge numbers of schools are hugely harried by targets and progress on SIMS than prior to my leaving. Figures, not kids, matter. Results, not kids, matter. It sounds daft, but the idea that one childs level 3 might be an Everest and an amazing win has GONE. Unless they are are SEN, SA+ and so on.
I coped by finding a small school with an ethos I liked. Like the old ethos: every child matters. They do still exist, but they are hunted out of existence.
I also went part-time. This saved me.