Being his wife can not be fun. Well, the new found millions probably ease the burden though I can certainly see him losing it all.
The dude is unstable.
Well, as a guy having already passed middle age and having been through it and all the classical foibles, I’d say that this isn’t just your normal middle-age crazy.
Frankly, if he weren’t a man, I’d swear he was going through “the change”, because I’ve been on the wrong end of that, too. Maybe there is a “change” for men?
However, given the lack of normal “change” medical condition for men, I’d say the man IS unstable as you opine, but I think he is also mentally imbalanced - seriously, in my opinion.