I also have a hard time evaluating these situations. Is it me or is it them?

The first thing I would do is try to figure out how I could better take care of myself given the situation. Sleep, exercise, good boundaries. I would also see if there is anything about the situation I could change i.e. would it be possible to form a committee to document standards.

I have also involved myself in extracurricular activities that were so much more interesting than my job that my job bothered me less, which doesn't really work if the job is making you so miserable that you don't feel like doing anything outside of work.

I'd be careful about how I framed this choice. It might feel like 'Do I stick with this job or go back to SSDI,' but it may be that while this job isn't right for you, another one is. It's sounded like it's been going pretty well in other posts, except for that one mistake, so maybe it's stress from that and being sick that is clouding your judgment?

I've found it helpful to list what I've liked and disliked about various jobs. There are probably some things about this job that are actually good. Maybe the downsides aren't so bad if you compare them to other jobs or the poverty that comes with SSDI.

Going on interviews and applying for other jobs is also a way to help evaluate where you are. I remember going on some that made me feel much better about where I was -- and having options is nice.