"He refuses counseling."
That does not mean that YOU can't go on your own.
What you both need, it seems, is not only couples counseling but parenting classes, especially parenting classes aimed at blended families where both parents are dealing with new stepchildren. And a relationship with a stepchild is so fraught with baggage on every side. (For instance, have you considered that he lets her wrap him around her little finger because he might feel guilty about her not being in her "first" family? Or that he feels he has to be an all-fun, all-the-time daddy to make up for hurting her? Those are classic reasons why a parent would let a child walk all over him after breaking up with the other parent.)
You also need help with your marriage because anyone who details her husband calling her the names you list, who then says later she's never been so happy in her life-- needs some help sorting out what's going on. He is issuing threats, saying he'll make a scene if you don't...do what? What he wants? That's controlling behavior; do you want to be controlled, called vile names, and wondering whether what you do and say will please him? Is that any way to be in a marriage?
You deserve better than this!
Please, please get marriage counseling and parenting classes. If he refuses to go, tell him you are going alone, but that if he continues to refuse to go, you will start having to think about your options regarding your marriage. Because....you WILL have to do that. Or you will have to go on lettting him call you intolerable things and letting him treat his child in ways that will eventually create a brat -- through his issues, not through any fault of the child's.
Your courtship was extremely short. Some couples spend much more than seven months just in premarital counseling to be sure they start marriage on a sound footing. Please let him know that there are two of you in this marriage and both of you need to get the counseling you would have benefited from before you got married -- especially with several kids involved.