Why did Waring Hudsucker commit suicide?

In addition to the blue letter, which mentions Sid getting the girl, Norville has a brief scene with Sid's wife (at the black tie party). She's a little hard to understand because of her accent and her use of French words, however she mentions a water cooler romance with "he who shall not be named" or somesuch.

I believe the intent is that Sid married Waring's gal and Waring, a man of immense wealth and power was laid low by love.

Hud was very very successful.. But I think he was lonely. Yes he had to die as part of the plot. But, as for the reason? It seems almost like an Ebenezer Scrooge thing. He kind of let being successful and being rich get in the way of being with the woman he loved. And it seemed from the letter he lost her to Sydney. He says something about taking care of her. So I always assumed it was just a combination of things, he was successful but lonely and feeling he lost out on his only chance for a life outside of his success.