I hate the cries of 'sexism' on here. OP is a man who chose to post on a forum for women. That is a choice. Would I post on Dadsnet for support if DH left work? Hell no! So, why do it? Charitably, because it is a huge forum for parents. Or, because he will get ammo to fight his DW, because he likes to goad women, because he wants to say we are all sexist, because he is good and patronising... I like a lot of the men who post on hear but a lot of them are here talking about parenting, sleep, school, whatever. Coming on to AIBU to talk about your DW? Paint me cynical. And, I think if a man left work after 18 months of sadness, depression would be the first thing mooted.
You are being cynical.
I occasionally post about marital issues because I don't want to bring them up with friends and family, and because this forum seems exactly where to post that sort of problem, between here and Relationships.
There may well be a Dadsnet. I haven't checked it out - I surfed here while looking for something else and stayed because the discussions are interesting. But it is still worth discussing things with women, I think - they might well have some insight into the problem that wouldn't be so obvious to a man.
For example, I posted a thread about being astonished when my wife told me at the station as we were going to work that she had applied for a job abroad. One of the comments was that maybe she was afraid to tell me, so she had chosen a public place. OK, that certainly wasn't the case, but it was something I would never have thought about otherwise.
I certainly wasn't looking for "ammo to fight my DW".