I follow a lot of the misery subreddits for some reason. The one with by far the most miserable, downtrodden, and depressing posters is not related to divorce, alcoholism, heroin, or anything like that, but gambling. It's not even close.

If it's somehow worse than /r/dph I'm afraid to even look at it

r/loveafterporn (mostly women married to porn addicts) is pretty depressing but worth following because once there was a post about how a user's husband bypassed monitoring apps on his phone by looking girls in bikinis on beaches in Google Street View