Suggest me a book about a soldier or an ex-soldier who is dealing with trauma. Something hopeful, not too realistic, grim or gritty. Soldier can be of any gender. Also, any genre is fine, from military sci-fi to romance.

I am looking for a book that will make me really feel for the character. It is fine if it pulls on my heartstrings but nothing grim-realist. Genuinely hopeful. It doesn't have to be all rainbows and sunshine, of course, just not something that will leave me depressed. Just please nothing that idealizes U.S. Army. [...]