I'm not sure that there is anything you can do other than what you are already doing- as you acknowledge it has been easier for him to avoid confrontation and perhaps counselling is something that will help him to understand why he does that and to accept that avoidance often just makes things worse.
No doubt you have your own reactions to the situation, but I think it might help for you to bear in mind that, though the situation has affected both of you, the primary reason for your boyfriend going into counselling seems to be for himself. He needs to be angry *for* himself and to express that himself; perhaps you being angry on his behalf stops him from doing that because he reacts to the confrontation of it and not what motivates it? He probably understands why the issue is emotive for you, but maybe it would help to state it to him and to remind him that your anger is about the situation and not directed at him. I think the fact that you know you aren't the most objective person puts your streets ahead of others in similar circumstances.