Whenever my 2 little peanuts get me to the point of wanting to STRANGLE one of them (cause they band together you know) I put the one who is being obstinate in the exercise pen with some fresh water and toys and go about my day until I cool down. Then an hour or so later when I start to feel sorry for them being alone in the pen I take them out and play with them for a few then groom or brush their hair or teeth or what ever I had to do. It usually takes 2 to tango.....but I know with my 2 the more intense I am about doing something the more they think I am JUST PLAYING and make more of a fuss.
I am sorry things got to the point of your little guy getting hurt (not that I haven't had to pull my hair out of my head to no avail with mine) but I always feel the thing that works best is to put them in a safe place while I cool off. Then we can continue form a negotiable stance.
Hope this helps for the future.
Tina