This book was helpful.

It's all the things you already know you should be doing/not doing, but presented in a counter-intuitive way that gives you a fresh perspective on long-held unhelpful thought habits. That may seem gimmicky, but for me, a person who hates the smarmy "health, wellness, and gratitude" aesthetic that internet influencer culture seems to be relentlessly touting, it was useful.

I know that holding onto anger hurts only me, and I know that a poor-me attitude leads nowhere, etc. but Paterson's structure and mirror-image approach helped me look at several things in a new way. Also, as an actual psychologist and not just a well-connected New York City writer, his understanding of how to actually help people seemed deeper to me than that of most self-help happiness gurus.