How do you deal with disappointment?

The biggest disappointment, for me, always involves my children. If it happens to me, personally, I am able to deal with the situation at hand more easily and set aside my differences. But, that's not the particular item that I'm struggling with. I have been tossing around the way I react to disappointment. I find that I react quickly and do not take a breath before my emotions get a hold of me and literally leave my easy going spirit in the dust. Almost always it is sport related. I am competitive. I am immersed in sports. I am very passionate about both. This can be a bad combination and the outbursts of emotion have reared its ugly little head on more than one occasion. Typically, I'm a quiet person, especially in public or in large groups of people. But, when I get mad or am denied a particular desire while in the heat of the moment, I just snap. I don't care who is there, where I am, or how loud or ridiculous I sound. It's like another person takes over. I'm no longer cognitively in control over what my lips spew and to who. It's quite like an out of body experience. One way I deal with adversity is to write it out, kinda like what I'm doing right now. This does seem to ease the tension quite a bit, but there are many times when the tapping of a keyboard or pen and paper are not readily available to allow the steam escape my molten anger from inside. I am consciously making an effort to take deep breaths and not let things rattle me. It's a tall order for me, but I believe worth the effort. How do you deal with disappointment?