Very unsuccessfully, I've been fighting this fight for over 30 years in and out of the care of doctors, luckily right now I have insurance so I'm just out copays and whatever fees the psychiatrist's office decides to send my way but it's worth it because I'm stable. Without professional help I pile on distractions, hobbies, overwork, volunteering, etc. Not a healthy coping strategy, I've tried to kill myself twice (the last time earned me a 4 day medically induced coma) and been put on psychiatric hold. I know you said poor people can't afford it but there are clinics where I live that deal almost exclusively with the homeless, if they can find a way to help them they may be able to help people in better financial positions who still can't afford treatment on their budget.

Edit: to address your question more productively, one of the things I've been doing on my own is writing to myself. I have been thinking about my situation and identifying behaviors that I need to change. When I go through my days I don't really consider my actions but when sit and really think about it I can see what I am doing that is toxic, then when I start to do it again it's easier to identify in the moment and attempt to alter whatever I would have previously done, e.g. when I am frustrated with something one of my kids has done I used to yell quite a lot, now I excuse myself to a quiet place, calm down a bit, and then go back to address their behavior. I haven't even seen my counselor since my last suicide attempt (less than 3 weeks ago) but I found that this has helped me immensely.