Perhaps, you may have depression?
Or, it could just be from whatever is making you upset it might be your friends or some sort of social life. Maybe something's wrong with your family? And perhaps you haven't learned how to express those feelings properly yet. <3
But, dont worry :) To calm down, listen to some music , dont thrash out on anyone or anything, drink some tea, sleep maybe, or play some sports :) Then you won't hurt yourself. :)
these are stress synthins, you need to figureout what theae stressers are, it sounds saver, you might tlak to a counsler.
ill try it, i havent learnt to express my feelings yet i dont think because i always keep it to myself.
Thats my problem, as well :) try writing stuff into a journal. sounds dumb, but it works :D
thats not dumb at all, i sometimes talk out loud aiming at my poster on my wall :)
Stress, remove some stress and be more positive.
thats cool :)