I agree with you, it does sound like he needs to grow up. If he wants to see his kids, he needs to get on the ball. If he stops the fight now, he could look pretty bad in the eyes of a judge. Remind him gently but firmly what is at stake here (like jail time and seeing his kids). Not to mention all the time and money you both have already put into this. Aren't his kids worth it to him???
Could he be depressed? I know with the court stuff this would be a bad time. If you want to avoid a doc or if he refuses, try natural methods such as excersize, massages, and tryptophan. Custody issues with my hubby makes him pretty depressed.
Help him out by doing whatever you can as far as paperwok and stuff, and encourage him and remind him of what the outcome would mean (having his kiddos around
As far as the disclosing info goes, thats something everyone in a custody situation have to do. But don't forget, anything your husband has to do the ex-wife has to do too. If he takes a drug test, the ex has to also. And anything he has to disclose, his ex does also. If she isn't at this point, you have every right to request that she does (and she should!).
Good luck to you guys and let me know how things turn out for ya'll.