You might want to read 'The Lady's Handbook for Her Mysterious Illness: A Memoir' by Sarah Ramey (Known also from her band Wolf Larsen). She goes back and forth between providing an overview of this 'mysterious illness' from different angles, and her gutwrenching absolute trainwreck of a personal experience of it. It seems you already found your way the same way she eventually did, though.
As the title says, the book is womens body specific - but also a guy i still found it very insightful to read.
Another book to suggest, "The Comfort Crisis" by Michael Easter. In it he does a solid and helpful flyover on how humans evolved vs how we actually live now, and how the disconnect is impacting (negatively) our physical and mental health.
While there are few individual ah-ha moments, seeing everything laid out end to end to end aggregates into a realization that The First World lifestyle is extremely unhealthy and often (premature death) deadly.
Fwiw, in some ways The Comfort Crisis was like physical (and mental) health version of The Coddling of the American Mind, but without the PC-ish type baggage. Note: this comparison - for me - is a compliment as both books look to challenge mainstream narratives and normalizations.
As the title says, the book is womens body specific - but also a guy i still found it very insightful to read.