I'm with you, Sister!
The Mustachian-related challenges:
1. If I eat an expensive diet, my mental health improves dramatically. When I eat a very cheap diet (starchy fillers), my mental health flatlines.
2. I can work a maximum of a few days in a row, and then I'm totally stuck. I have to wait the stuck out before I'm productive again. Obviously, this affects my income rather dramatically. At this point, I am simply being patient with myself, telling myself I will get it all done -I'll just take a year or so to do what some other people do in a month.
The Mustachian-related positives:
1. I am able to access a lot of free resources and income supplements. They add up and help a LOT to give me a better quality of life.
To answer your questions:
I do fantasize about a regulated lifestyle, but habit-building seems to be a no-go for me. I can, though, do a push/coast/push approach.
I do what I can, with a focus on physical survival (including emergency savings) for my son and I. I let go of the rest. And I mostly love my life! Letting go (of extra goals, etc) is key for me.
Optimism - I can get discouraged, for sure, about what I don't have (internally and externally). My trick is to then take inventory of what I do have, e.g., gratitude practices. I'll make a physical list of what in my life I love, or the advantages of my mental illness, or the benefits of, er, involuntary simplicity ;)
Support network - I often want to curl up in bed, but having a kid eliminated that option. His existence gets me up and out. If kid-less, I would (and did) use meetup.com to meet other people who understand/experience mental illness. Some groups I've found that fit this are those focused on "nerds", "geeks", "shy", etc. The terms are used kindly, and bring folks like us -many of us who experience anxiety, depression, etc- together. We get to commiserate then laugh! This helps with self-acceptance, as well as with locating resources we may not have known about, etc. Start with an easy one, like board games where you fit without having to be very social.
Self-care - I limit it. I eat and try to make myself sleep, but otherwise I accept the offers of others to care for me. Mental health agencies, the crisis line for listening, the government with its subsidies, etc. I'd rather be wealthy enough to pay for private help, but I'm not, and I trust that the folks that offer these services do so because they want me to be well, so I take them up on it.
Something simple that really helps me is to clean up my place. That single move can usually take me from total overwhelm/depression to peace and calm and happiness. Or visiting someone who is struggling more than me.