The guys defintely not coping with the changes he is facing. Its better to get ahead of that stuff. As for the PI, I wouldn't normally suggest that to someone but in this case this guy seems like he is blaming himself. Based on his discription of the past few years the chances are good is wife has a friend on the side. If he know this it may help his conscience that it wasn't him that wrecked the marriage.
As to the shrink, Just because she is a slob and spends you into the ground, there are issues on both sides and you both are valid... never seemed to help much. See a pastor.
As to the PI, If there is a boyfriend I suspect he will surface to flaunt himself and be the White Knite, especially since being a man means you start at the bottom of the 9th with two strikes against you and it is hard to fight back anyway.
While the courts "allow" you to see your kids for a few hours you get to drop them off at your former house to your former wife while her new "man" gloats because you can't do crap about it. Homocide may come to mind, but your kids wouldn't be impressed, so you don't.
Save those funds for other things.