This might sound kind of silly, but it might help you a bit. Go to the store and get one of those inflatable punch toys (or two) and beat the hell out of it. I'd say get a punching bag but given you live in an apartment that doesn't seem like an option.

When I was 15 I asked my mother to take me to see a mental health professional, but she refused, insisting I was fine. I was actually pretty mixed at the time. I did, however, convince her to get me a punching bag which we hung under an overhang in the back yard. It helped me channel my manic/mixed rage in a way that didn't hurt anyone or break anything.