Don't be ashamed for losing it. You have been stretched very thin and are a ticking time bomb...maybe it was a matter of time. Of course, there are different ways to manage the release of the built up stress, but even the best of us do lose it from time to time.
I don't necessarily think that when we "lose it", that it means there is something that needs to be fixed every time. However, I do agree with the above suggestions to give up a thing or two for a while...take a break..take a breather.
