> "what happens when you, well, don’t have the laundry done, and you realize you actually really need a clean shirt? (Or whatever.)"
Sensible answer, ideally you say to yourself "I don't have a clean shirt, what options do I have?" and consider the best available option and use it, absent the self-hatred and judging and putdowns and bad feelings and stuff which isn't helping anyway.
[Edit: I missed something major in this response; it's not necessary to make all the bad feelings go away entirely and be happy with everything. It's more that you can choose - if feeling bad does help motivate you to do the laundry, keep some of it. It's the "I didn't do laundry, I'm 100% a terrible person, a lazy slob worse than everyone, I fail at everything I don't deserve to live, woe woe" spiral which is an overkill response. You might decide to keep 50% intensity self anger, or 10% intensity self-ticking-off or 5% intensity self-eye-roll. Whatever you decide is enough suffering to be motivating, if any.]
Figuring out a way to get the laundry done should in theory be easier once you are not being bullied by yourself.
(You can also substitute any X, where X is not harmful behavior, for "slobbery".)