What I had in mind-- and it may be unfeasible-- was to do what you can for your situation without trying to revise yourself.

Yes, we definitely mean different things when we say the same words - I've always embraced an 'extended' view of self, where my self and my situation are utterly inseparable. In my ontology, the phrase "do what you can for your situation without trying to revise yourself" literally has no meaning.

What happened when you gave up on self-improvement?

in a word, entropy.

To elaborate, I stopped trying to tweak my psychology so that getting up in the morning could be bearable, stopped expending willpower and brainpower to seek delayed gratification, stopped playing mental contortions to emulate hope, and stopped putting forth a mask to everyone around me that everything was okay. In response, what meager social networks I had established eroded, what meager opportunities I had to feed and house myself eroded, and what meager opportunities I had to quell the screaming in my head eroded, and I eventually settled into a new, lower-energy ground state.