That first job offer you describe sounds like they simply weren't prepared to be as flexible as you needed them to be. I suspect it had nothing to do with full-time or part-time; only that beyond a point, they weren't prepared to be more flexible.

Perhaps something part-time and local would be more up your street, even if the money's not very good. If there was someone sympathetic to your circumstances and close to home, so you're not spending hours travelling, that'd be much better.

Saying that, I'd hoped to work locally for years and never achieved it, until I went self-employed as a writer. I wonder if you could write blogs for autism organisations or something - I'm trying to think of a niche where you have specialist understanding that they need, and could command a worthwhile fee.

Also, it might be worth keeping your eye on writing jobs on job boards, because although they can sound demanding, there are a lot more people prepared to let you work remotely these days. And it says so in the advert, if that's their vision.