'Human are stupid and it's interesting to watch their stupidity.' They tease you?
Because they are jealous of who you are.
They bully you?
Because they are weak and want to have superior over someone. So don't give in. You are stronger than they. That's why they want to take you down. So raise you head and show the how strong you are. Put a stop to bullying.
Cyberbullying?
Well...they are just that weak that they can't even say it to you face-to-face.
You're cutting yourself?
Is cutting fun? You're just doing what they want you to do.
Are you fine with them controlling you?
No? Then why don't you just break out of that small bubble of yours and seek for help? And get your revenge?
-Izaya's wise words (probably)