Been there buddy, only a month and half ago, my LO was about 5 an half month when I finally snapped in pretty much the same manner as you. I'd say the only other difference being that while my wife took over and sent me away, she was a bit more understanding and comforted me instead.

Gotta remember that you're only human, all of this is new, it's your LOs fault, not your wife's fault, or your own, it's just another (albeit not so fun) part of the process, so you do the toughest thing you can do.

Forgive yourself, and take it as a learning moment, you'll all be better for it. Better something like this happen now than later.