This is a self help type of book. It functions well as a sort of kickstart for traumatized people. It says, yes, you are surviving, you made it and you're considered functional, but let's admit it, you're still a bit permafrozen and it's time to try some life. It's written by a traumatized person, rather than a patronizing person, which is nice.
It has some advice in it that I haven't heard anywhere else, which was massively helpful. The best bit of advice, in case you don't read this book, is to carry a rock with a spiral on it and to touch it when you notice that you have spiralling thoughts.
I think an easy trap to get into with mental health issues is to take it so gravely, care for it so gravely, building your shelter, that you forget the next step is to give yourself food and sunlight.