First Man In by Ant Middleton https://www.amazon.co.uk/First-Man-Leading-Ant-Middleton/dp/0008245711
This book is about the life of a man with a rough childhood. He enlists into the army which like many who do, gives him structure to his life, but after a while he is left floundering with a loss of meaning in his life especially with the demons of his past that he hasn't yet faced. Ultimately overcoming them all and the obstacles that he has had to go through in his life, he gifts the reader with a lesson that each chapter in the book and essentially his life has taught him. And it's a true story.
It nice because it feels like a nice story read but it's real so the advice he gives, you know is warranted because this man has gone through a lot. My situation was not similar to the guy in the book's at all, but it helped me. I urge you to maybe gift it to your gf.