I am in very bad books with my headteacher as you can see ( he wrote me a reference and then I pulled out, so he knows that my behaviour affected my current's school reputation)
I am thinking applying next year. BUT I am completely exhausted with stress etc. Also, have problems with childcare ( under 5 kids). I wonder whether to request a leave due to childcare for under 5s ( 6 months or so?)...
It would be unpaid. You could ask for a term or year as leave of absence - no harm in asking. But don't be surprised if they turn you down.
In the meantime, I honestly think that you are overblowing the whole withdrawal from the job thing. It is not an everlasting mark of shame to accept a job and then withdraw. The idea that it has affected the reputation of the school is ludicrous. The other HT has probably already put it to the back of your mind. Teaching recruitment processes are odd, very odd and out in the 'real world' this would be a five minutes' wonder.
Your current job seems to be unsustainable so, in your position, I think I would just resign now for Christmas (school will appreciate the notice) and look for another job to start then.
If you can't cope with the Autumn term spend it signed off. Have you been to OccH? They should be working with your current school to make adjustments that will enable you to do your job without becoming ill.
You are totally over thinking the withdrawal thing. I know of somebody who has applied for and then withdrawn from 3 jobs this term!! DH writes the persons references so it is work for him but he's more of the mind that the person needs to find the right job for them than feeling pissed off.