He does his own washing, cooking and ironing and he pays some money for board....you're doing better than a lot of people so far.
He probably does not want to discuss his problems with you and you certainly cannot get a social life for him.
I can only suggest that you ignore his negative comments etc and praise his good points.
The most positive (and very difficult) thing that he is doing is going for counselling. Make sure he knows that you respect him for doing this.
Tell him that you appreciate his doing his washing etc.
If he is depressed, which sounds likely, his bad attitude may not be entirely under his control. Irritability and grumpiness are symptoms of depression and are often visited on the ones closest to the depressed person.
Being threatening and horrible will not do any good. It will just antagonise him and make you feel guilty.
Hang in there . It might take a long time, but he will come out of it in the end.
One final thought..and not a nice one...do you think he blames you for the earlier abuse ? and do you think he has reason to ?
If he does, then it is an issue that I would expect his Counsellor would go through with him.
If you think he has reason to, it is something for you and your counsellor to discuss.