Hi K..
What you are experiencing is a lot of conflict. You want everything to run smoothly without anyone being angry. Makes sense. Who doesn't? Unfortunately, as you have described your husband, this is not going to happen until you BOTH come to terms with his issues.
You're right: He needs counseling, without a doubt. And, (please know I mean the following in a gentle, 'I have been there' way): You need to face your own issues as to why you don't want to confront him. Do you have yelling issues? Why? How does it make -you- feel? Is this why you don't want to put your toes too far into the water and begin to solve what is happening in your home?
My suggestion would be -- Have your children some place else for a couple of hours. (Not just playing outside. You must feel confident they won't just pop back in.) Start the conversation with, using a calm, soft voice; "Honey, I'd like to talk with you about something that's been bothering me. First, I want to apologize for not having communicated more fully to this point. I plan on being better at it in the future...I need your help. When XXXX happens around the house I don't know how to act. It makes me feel XXXX, helpless, unable to defend my children, not part of the solution, etc...I know you are working on a more calm delivery of your message to the kids. How can I help you with that? Is there a secret signal I can give you, or something? What would work best for you?..."
The basic message here is -- You are trying to solve the problem together. AND, you are willing to do your part; you are going to start telling him how the yelling makes you feel (out of control, overly protective toward your middle son, like a child, whatever), and how he needs to help you past those feelings by understanding them, speaking in a more calm voice, and perhaps even suggesting YOU handle the situation vs. his stepping in.
Anger is a very tough emotion to set aside. It takes A LOT of concentration and self discipline. It also takes the people closest the 'offender' to be willing to say I am not willing and/or able to tolerate this behavior. I am going to stand up for my rights and those of my children not to be verbally / emotionally abused in this manner. (Keeping in mind angry words and challenging stances will teach your children this behavior will be tolerated and adhered to. Do you want that? Does your husband?)
I do not believe making your husband 'pay' for his behavior or making threatening overtures (such as, "I can't be married to you if you're going to continue..."), is what you need. The man is making strides in his behavior -- be absolutely sure to commend him on this!!! And, as we all know, half the battle to fixing a problem is recognizing there is one. :)
Oh, l'est I forget: Be sure you're not over protecting your middle son. You may be doing that unconsciously. He may (in at least a small way), have a tendency toward the less desirable behavior because he has learned he (ultimately) has Mom to protect him. All discipline and punishment should be administered evenly. Ask yourself, 'What if YYY did this? What would the discipline be?'.
Good luck, K.. It won't be easy to make yourself open up to what you fear. But, you will find it is the -only- way to get past that fear.
My best,
K.
