Hey Dadslib, can I add my tuppence here? It's not so critical so don't worry! You say your dw can be provocative, let me tell you what provocative is! When I was going through pre-natal depression I was EXTREMELY provocative. I would call dh something rotten! I would hit him with my fists, I would scream at him, I would smash things, I would say horrible things about the baby inside me, I would tell him I hated him and that I was leaving him, etc, etc. At this time neither of us knew what was going on and at times I did get him very angry, angrier than I've ever seen him. But not once did he raise his hand to me. He pushed me a couple of times, mainly to stop me from hitting him, but he NEVER retaliated - and I sure gave him just cause to do so!
Of course people have come down heavy on you here. You are posting on a site that is mainly frequented by women - some of whom have been (or still are) victims of domestic abuse and they have listened to their partners tales of remorse, and they have been accused of being provocative. But you know, really, there is no excuse for violence. I had no excuse to be hitting dh, I had no excuse at all. Luckily this time things haven't been that bad, but I have still threatened to leave and I have still tested his patience beyond endurance. I love him all the more that he has stuck with me and seen this thing through to the end.
Please do go and see someone. Your local hospital will run anger management courses. If you find it difficult to deal with your wife, I am wondering how you deal with your son, after all toddlers can be just as provocative can't they? If you manage not to hit him, then surely you can apply the same strategies to your wife.
You are not a bad person, I can see that by the posts you write. But you do seem to be under a lot of stress and it is contributing to the way things are now. So don't let it spiral, don't wait until your dw leaves you taking your ds with her. Take action now. You've been saying that to SS, now is the time to take your own advice!
Best of luck.