I'm also having a bad time with my job. Sometimes that's all it is. I wouldn't call this a quarter life crisis though. Tell him he needs to think about getting another job if it is depressing him to the point of affecting your relationship. I'm in the process of leaving mine because it depresses me and affects almost every aspect of my life. Sounds like he's in the same boat. Just be there for him, but tell him that he needs to quit for the sake of your relationship and your collective happiness.