New Name - I decided I wouldn't post again until you did something. You've done it - you've got away from him for a few days and you've contacted a counsellor. Now go and see that counsellor (promise?) and do it on your own. You don't need him there and I don't think he'd add any value to it.
Stay away for a short while longer. Hopefully the drug free you is now kicking back and seeing things more clearly.
I've often said on other posts that betrayed partners should do the maths. and work out whether an affair was truly aberrant behaviour or whether it was simply a continuation of selfish and abusive behaviour. Even if it works out that it was an aberration, the betrayer must do everything to make amends, restore trust and love and care for the person they have betrayed.
Based on what you've said, your H fulfils none of these criteria. He's always been a cruel, selfish git. His adulterous behaviour is hardly aberrant if he crossed the line with your friend, he has refused counselling, lied to you in the summer about contact with OW and failed to support you when you were dealing with a humanitarian crisis with your son's friend.
He has got no bloody right to be pissed off, but I sincerely hoped that your actions might make him finally wake up to the consequences of this behaviour. Instead, he is taking your bait (I wonder why you did that?) and is probably getting comfort from someone who is no friend of yours, or your marriage.
Try to look at this rationally for a moment - you have accepted really shitty treatment from him and your friend. One of the things I hope you will gain from counselling is that you'll never let anyone treat you so badly again.
I don't see any hope for this relationship, but I do see hope for you. I wish for you the strength to see that you WILL feel better without him as your partner. It will take enormous courage and willpower, but this man's marching orders are long overdue IMO.
Keep telling yourself, you are a good person, evidenced by the way you mother not just your boys, but all their friends. You have a great brain and although you can't seem to see it, you have a great future ahead of you.