Whenever I start slipping into, or am deep into, one of my "WTF am I doing???" meltdowns, I keep on reminding myself "I know what does not work". I spent decades trying things one way. My life was not working. In fact, after a few decades of insanity, you can say I didn't even have a life, I was barely a machine.
Today, my life is working. I feel alive. I experience joy. All due to few 'minor' tweaks, some hard work, learning about and using some new tools, and trying to unlearn bad behaviors.