Trivial World Be Damned

Why is it that I lose sight of what is truly important so quickly? For my sake I hope I am not the only one but for the sake of the world I hope I am. Trivial quandaries in my life take me spiraling down into negativity. I am not an angry person. Few things actually push me to react negatively. But one that does is stress. I curse, I punch, and I take it out unfairly on people that deserve much better. I always regret my response to these problems shortly after they are resolved but how can I control myself in the meantime? For instance, today my car broke down. I, as well as my girlfriend, strongly rely on my car and without it my life seems handicapped. But I know it shouldn't be this way. I started cursing and gritting my teeth until I couldn't unlock my jaw to say a single loving word the passenger whom means the world to me. How is it that I lose sight of the goodness that surrounds me when this one material thing gets in the way? I am incredibly disappointed in myself. I shouldn't get lost in the trivial world. A car is not the source of my happiness so why should it go away with the engine? I expect myself to be able to keep a peace of mind despite these things but my stress takes me places before I know where I'm going.