lilybeth, you really do need to do something, and I don't think you need anyone here to tell you that.
These sites probably aren't illegal - they are known to use young-looking models and actors who clearly aren't related to each other. And for most people who view them, it's just a harmless fantasy. But if this man is going further than sticking his hand down his trousers whilst watching, then you need to ask how long before it affects not just you (which you say it already has), but your daughters as well.
It's quite usual for anyone who has an abusive partner to find any number of reasons for not getting out, and professionals do understand this. It is not a weakness, just an indication that you need help. However, like an addiction, escape has to start with you. You should not feel ashamed or guilty at going to whoever you see fit and asking for help. No-one will blame you or think ill of you - no-one that matters, anyway. Believe me, he has more to fear from 'everyone knowing' than you do.
Re. your counsellor putting it 'out there' without your knowing first, remember that he/she is bound to keep the matter in confidence until you say otherwise. The only exception is if they think your girls are at risk of harm, in which case it is the counsellor's (or their manager's) duty to inform social services. This is the law. However, that could be just the metaphorical kick you need.