I'm also not working at anything, and down to brushing/flossing once a day and showering every other day, but the feeling I get from that is not so much disgust as a feeling of helplessness and fear that I won't be able to take care of myself. I live alone and don't have the kind of friends who would be in a position to help in practical terms, so the fear is coming from an additional situation, isolation.

I'm suggesting that disgust is not the only reaction to this situation, so there is some other factors that contribute to the disgust.

Try to take stock of what you do for yourself and then, well, add one small thing a day.

I worked out a system when I was on chemotherapy and actually relatively mentally healthy because i thought other people actually cared about me. It was a point system.

1 point for taking a shower
1 point for unloading and loading the dishwasher
1 point for going shopping or to appointments
1 point for going for a walk

I also had a fitbit, and some days it was all I could do to get one point for the whole day.