WherecanIhide, this is about power, and someone in a position of power abusing you and your children.
You used the word grateful in reference to the sort of man you thought you had here, and I am concerned that there has been a major power imbalance in your relationship up to now (thinking back over WWIFN's earlier post re communication here too). If you really thought you seemed greedy, then that is very sad indeed.
Please do not bother yourself with thoughts of your H's so-called problems, addiction or depression or impotence or stupidity. You have much bigger problems than he ever had or ever will at this point. He is a vain, stupid, angry and cruel jerk who has deliberately chosen loneliness by checking out of his relationship with his own wife (impotence my eye) and his children over all these years, with his night owlishness and his fondness for chatrooms and dating sites.
Please do not waste your time worrying about his 'addiction' or isolation when he moves into a flat by himself. He has plenty of people to talk with about what you should do wrt getting a job, plenty of colleagues no doubt willing to lend an ear to whatever poor me routine he will dream up to explain his new address -- while you have no family or support in RL to rely upon. Your focus must be you now, and your children.
If he chooses the chatrooms, so be it. He is out of your hands and he has been for years.
Stop worrying about this man. Stop listening to him talking about your relationship and stop talking about what made him do it. He doesn't care why he does it. He is not looking for insight into his shitty behaviour here, or insight into how horrible all of this is for you, and he doesn't want to hear about the damage he has done to his own DD. He obviously does not agree he is a piece of shit and he is not repentant at all. Your opinions do not matter to him.
Please do not tip your hand to him about what you're doing with the CAB materials. Keep your plans to yourself. Do not try to impress or intimidate him by telling him about your support or the advice you're getting. He is not a nice man, and he doesn't care how he has hurt you in the past or how he may hurt you in the future, or your children.