Welcome!
Does your husband still believe it's the truth? Would he read Crisis of Conscience by Raymond Franz? Or Apocalypse Delayed by James Penton? That may ease the guilt he has, that he's doing the wrong thing by granting himself some happiness. When he realizes how the organization is run he'll probably feel pain and anger, but will be freed from guilt and remorse at not seeming to ever be able to measure up.
According to the Bible, Jehovah is a happy god, and there is love among his true followers. If a person isn't happy and isn't loved by those members of his religious organization, they cannot have the truth, no matter how many times the WTS says they are God's channel of communication. If the love isn't obvious, then it can't be the right religion. And it is not the individual's fault if they don't feel that love - the Bible says that agape love is extended to all, not a select few within teh congregation.
Therapy will help - so will this board.