Uncontrollable anger when loseing at anything?

Its usually video game related but it can be more, i'd like to say its just competitive but its not, i can just be playing guitar hero and lose at a song and i get extreamly fustrated and either start screaming and cursing at the tv or if theres an unlucky person around who says something to me at the wrong time ill rip into them really rudely, i hate it and its really upseting not being able to controll it. Then my boyfriend gets mad at me and tells me i need to learn to lose but i get so angry i cry because i cant controll it. i think its just a game calm down its stupid to be upset but i still get worked up eventually ... i tried breaks i stop when i get angry but i still get angry... i dont know what to do i always fight with my boyfriend because of it...