The Charioteer (1953) by Mary Renault, tells the story of Laurie Odell, a WWII soldier who was wounded, and now is recovering in a hospital, where he meets and falls in love with a conscientious objector, who is a deeply religious Quaker. He also meets an old school mate he admired and fellow soldier, who also is homosexual and is comfortable with his sexuality.
Laurie struggles with his romanticized view of love and a more realistic path to happiness.
I am rereading this right now. It is just so beautiful and romantic. I love Mary Renaults books about Alexander the Great, but this is my favorite of her books by far.