i think your depression and work stress is having a huge impact on your relationship.
Is there someone you can talk to, like a therapist about the depression and stress?
When I've gotten like that i am miserable to be around and it affects my marriage in a huge way. i go through feeling exactly like you that the relationship is ending.
it's a horrible situation to be in.

I would strongly suggest taking action if you are at all interested (which it sounds like you are) in saving your relationship.