Please be careful. When you return your manager will still be there and will probably behave the same. I was also bullied out of a job once and it is a most harrowing experience and hard to bounce back from. Please check out the website BULLYONLINE, where you can read about bullying in the workplace. It is rife in the education sector and those who complain usually end up losing their jobs. So please be careful and clever and do your research before going on the attack.