Get his hospital and treatment records for when you go to court. And get them CERTIFIED. i didn't get them certified and they weren't put into evidence, therefore suddenly when he said he doesn't have a problem, he appeared to be telling the truth. Also watch out for the "she made me go to treatment and promised she would come back to me if i did. that's why i went, not because i had a problem."
just some advice. It took me two years and a loss in court (although it sounds like you have more evidence than me) and i finally won, only because i gave up receiving child support from him
good luck!