Have you thought about or suggested a job share situation to your boss? My job also needs to be full time, but when I was returning to work I discussed job share and luckily for me, the woman who had been doing my job whilst I was on maternity leave also wanted to work part time.

Just another idea to put out there, I know there are a lot of other people out there who are after part time work so I am sure you would be able to find someone to job share with.

Good luck.
Janie xxx