Poll: he's getting on my nerves?

Me and my bf has been living together for approximately 6 months. But there's a problem.

Whenever things don't go his way, he gets into a fuss over it. Like one time we were looking for a store and when we couldn't find it, he gets really angry and cusses. Even once he broke his yolk for his eggs, then he threw a fit over it. A lot of times he considers his day ruined over something so small, it kills my mood at the same time. He gets mad over small things. Then he tells me to stop being so negative? What's his problem? What can I do whenever he gets mad over something?