Well, I'm in my adolescent years and I know that this would come up after some time.
The problem is that I cannot control my anger after sometime, like even when I'm being perfectly okay and just finished watching I'll suddenly feel some enormous anger to someone whom did things that I didn't like (Like forcing me to do things and stuffs), I don't show this anger by any physical means tho. So after sometime I felt that anger, when I talk to someone I sometimes change my accent (Involuntarily) to somewhat angry voice (Even if the conversation is going well) then they'd ask what they did wrong then I would suddenly realize that I spoke like that.
I also cannot stop the lust of thinking to kill someone, by just means I just punch the wall if no one is around to relief that thinking. I really don't want to open this up to my family or friends since I know they would be worried.
My question is how can I stop this sudden mood swings? (I can provide more information if needed)