There are times when I think he's just a shut-in asshole but at the same time, I'm sure there's quite a few shrinks that would like to poke and prod Phil because the way he ticks is really unusual, and not so much in the gin at 3am and eating junkfood while playing videogames / watching netflix all day because that's really not unusual in people with depression and little self-control, but the way he shuts down anything that might upset the narrative he has playing in his head.
It's clear he doesn't want to lose the house because it will destroy his sense of security, in both his life and himself. The status symbol is one thing but the house is a place where Phil has control and my guess is that Phil likes control but has little means of attaining it, he has no drive or charisma to want to gain control so he's sort of made his nest and from there he is in total control of his life and his community. If Phil didn't have twitch or youtube, I really can't imagine him ever leaving his house at all, the very idea of it is a chore to him.
But Phil refuses to take any advice and insists on self-destructive behaviors. This is commonly seen with addicts where they'll binge until their body gives out, they want to overload themselves because they try so hard to beat their addiction the end up swinging hard the other way when they give into them. Phil seems to act like there is nothing he can do, while there clearly is, so instead will go down hard with the ship like an alcoholic drinking their fifth bottle of jack before the liver finally gives out. I really can't figure out why he'd want to let his precious safe-space go up in smoke, out of sheer stubbornness that everyone else picks up the bill would be accurate for someone with a narcissist disorder but Phil isn't a narcissist.
Phil knows what he is, by staying in his house he can control this. He knows he is debt-ridden, overweight, depressed and friendless so when people troll-cheer or @ him on twitter, he is capable of shutting down that criticism with a block. He has all the power he could want to control his interactions, if he had to deal with people on the outside then there's no way he would be able to control the situation, fuck knows if he can even carry a conversation. Narcissists will think they're the smartest people in the room but are not often as vindictive as Phil, Phil knows he isn't smart but when he's alone in his office and is able to shut-down anyone who says otherwise then what he says goes.
It's clear he's massively insecure, just looking at how often he talks about his work, the price of his things, how busy he is and how much effort he goes through, he's trying to impress on everyone and himself that he is very busy and hardworking. He constantly repeats the lie to himself and when he's got this perfect air-tight environment where he controls everything, he probably starts believing it. Maybe. There's the occasional chink in the armor where Phil gets totally bamboozled and he will never let it go because he remembers any slight to him like a goddamn elephant so he knows he isn't all that hot shit that he constantly tells himself.
So to keep up this constant cycle of Phil being right, everyone else is wrong. Black and white, yes or no. Phil doesn't know the question, Phil doesn't answer the question. People offering Phil better advice, that might suggest Phil make changes that -aren't- from him! Loss of control after years of being in control, no no no. Phil is always in control of what he does, things that go wrong are outside actions that didn't occur within Phil's sphere. All that debt, sure, but Youtube and detractors and no sponsors meant Phil didn't get the bags of money with the big dollar signs on them, so Phil is still in control and totally didn't fuck himself over. Why would Phil trip himself up, he's the best person he knows!
Phil knows he can shake the can to make the money come in, it's worked before so it'll work again. People who say different are likely out to get him or fuck him over because only Phil can be trusted.
This probably isn't what Phil is telling himself directly but wrapping himself up in all this bullshit for fuck-knows many years with so little outside influence to check his mental state has left his actual view of the outside world so warped, he's the equivalent of a tupperware tub in the back of the fridge. It might just be boring old mold or something truly weird and different, but at the end of the day its gross and no help to humanity.