I think I get the concept you're putting forth with the phrase "first person syndrome".

I'm thinking that means something like "main character syndrome" where the person sees themselves as the protagonist of their own life, often to the detriment of others. They have a lack of empathy, attention-seeking tendencies, self-centered behavior, and often view others as supporting cast members in their personal "movie". Key signs include an inflated sense of self, a constant need for attention, and an inability to see situations from other people's perspectives.

There's a hedonic treadmill component at play compelling him to seek validation.

He has a hole in his life and he feels like he shouldn't because of how successful he's been. I wouldn't be shocked to discover that he's an alcoholic.