Heartbreaking.

I think depressed people have some fixations from the past. I know that my ex has a soft corner for some girl he had crush on when he was 20, said girl is now married with 2 children. He also mentioned (long ago, when we had started dating) that he doesn't know what the future holds for him, it's possible that he might marry let's call her Jane. Over the next few months I realized that Jane is a friend from his university days and she is happily married with 3 children! It's so bizarre. I think he finds a lot of comfort in past loves from his non-depressed days. It might be the same case for your ex. There may have been a few years he was non-depressed with his ex-wife and he associates love and happiness with that now.

When a person suffers from anxiety, they want to get rid of everything they associate the anxiety with. In his case it might be his current relationship (i.e. you).

Ahhhh... can't make sense of it.

Hugs!