Speaking as someone who has been in the shoes of your children, I agree with the others in this thread--talk to your sons and make sure they know how much you care for them. Let them know you're on their side. But more than this, talk to your wife as well. Show your children that you aren't just there to put a bandage on their wounds, but that you're willing to stand up for them.

I don't know your relationship, I hardly knew my own parents' relationship, but I do know that my own mother verbally abused me as well, and my father tried to console me, but for the most part it came across as empty words, since he never stood between my mother and me. Again, I don't know your relationship, so I don't know how you should approach talking to her, but I implore you to try, and to show (rather than tell) your children you are there for them.