I was the same way at 13. I made up another life in my head because mine was so ****. I was a liar from hell and I had all kinds of aliases online. I would go crazy and destroy everything and set things on fire too, I also attempted to murder my brother several times. They had to get him another door because I literally kicked it down on top of him then stabbed through it hundreds of times with a butcher knife trying to kill him. When I had those fits I was always laughing crazily and I'm sure I was super manic. I was depressed too then, no body gave a **** about me.
I was diagnosed as Schizoaffective Bipolar when I was 19.
I think you're bipolar honestly because you remind me of myself at that age, but who knows, let the doctors do the thinking.