I'm very sorry it feels this way to you. It sounds very painful.

Out of curiosity, what makes you think it's that he hates his job? Has he said something to suggest that? It's also possible that something is going on in his outside life that is distracting him or making him be less available, in actual time or emotionally. (For example, a family member being ill, relationship issues with a romantic partner or spouse, etc.). I'd try talking more about what it feels like from your end (but know he may not be willing to share if it's an outside life thing).