Please think carefully about that, Angelof29th, I was 'pushed out' or would have been but already had a new job lined up in the private sector which I've happily been in for 15 years. One of my colleagues was pushed out.
Agency staff came in as the council was put into 'special measures', agency staff put above my colleague to manage and she was bullied. She went on sick for almost a year, got about £30k in a payout as well as her salary - and went on to a new job elsewhere as a promotion.
If you walk out now you will I think regret it. You have a long-standing history and reputation and you deserve to be treated with respect. Your line manager needs pulling up, not by you but if you just go they will think they've won. If you go on sick leave you will have time to think and consider and can put together a case for HR. Councils are notorious for bullying behaviour and allowing it to fester.
Certainly do look around for a new job but do it whilst you are on sick leave and make sure that you get time to rest for yourself.
Are you in the union? That is something else to think about if not. Bide your time, gather your evidence and then WHAM, hit them with it.
I hate seeing women being bullied out of their jobs, it's not on. 

for you though, I know it's painful and a shitty time but don't let them get away with it.