I don't know how to decorate my room!?

Go to your local paint store and get a few paint samples, try them on your wall. Mainly tan or medium tone colors to make you feel calm. After you narrow them down to a few, see how they look next to your floor and then change your bedding. The anger issue is common with people around your age. Its not normal if you dont go thru that stage in your life.lol. If you like green then Dry Sage from benjamin moore is a good calm green for you or woodlawn blue if you choose blue. Change your light bulb and that also can make a difference on how the room looks.