The video is terribly sad, but I watched it through because it's also incredibly courageous. He's had depression from a young age. He's dealing with it in all the good ways that one would want to see: counselling, medication, exercise, even this candid talking-through of his present struggles.
Regarding the Civ VII part of it specifically. The state of Civ VII complicates matters for him. He says in the video that his favorite thing to do is just make a Let's Play. When the fanbase liked the game (VI), they therefore liked his Let's Plays, and said so in the comments, and that gave him a lift. Now, for the people who don't like the game, his publicly liking it (which is the starting assumption of a Let's Play video) means that he gets their abuse: that he's just shilling for Firaxis, downplaying what they think are the faults in the game. So now the bulk of the comments that he reads bring him down rather than lifting him up.
In my (unprofessional) opinion, he needs to do two things. First, at least for a while, he needs to do what some streamers do and hire someone to filter out the toxic comments on his behalf.
Then I wonder if the following might work, a slight re-casting of the basic frame of his Let's Plays, in the form of "Here's the fun that can be found in a Civ VII game, even in its present state, if you want it." He can acknowledge that the game has flaws. He says at one point that he himself has a variety of criticisms of the game, and even means to do videos on those criticisms. Anyway, acknowledge that the game has flaws, but say "here's how you play around the flaws and have fun anyway." So maybe it's map-settings, or civ chosen, or opponent civs chosen, or self-imposed playstyle that let players have a kind of fun (and then use the Let's Play to demonstrate what that kind of fun is).
That would eliminate from his audience those who simply don't like the game, because his starting framing is that he's doing this only for those people who want it. It draws a distinction between him and Firaxis: I'm no shill; I acknowledging the game's flaws; I'm just showing you how to play against them so that you can still have fun with the game. It gets him back to the thing that used to bring him joy: exhibiting the joy he takes in playing a game. It becomes a little meta-: I'm not just showing you game strategies; I'm showing you strategies for having fun with the game even despite some of its flaws. But that's all in the framing; from that point on, he just does what he's always done: play a game and talk about it.
This would have the effect of dividing his audience in 3: people who like the game so little that they wouldn't even watch a video of him playing against its flaws (and he can now completely ignore that group); people who like the game and like his videos; and people who don't like the game, but could be drawn into playing it if he gave them this method of doing so.
Hope he quickly gets through this tough stage. Since he's been struggling so long, he's acutely aware of exactly what he's facing, extremely detailed and articulate about the way depression sandbags him, and that should be some help.
He needs to take Ireland's housing situation off of his own shoulders. But that's something that's easy for an outsider to say, and no doubt harder for him to do.
