Is it a bad thing?!

Is it a bad thing?

is it bad that i ignore my anger until it builds up and explodes and i end up hurting myself by say putting cigerrets out on my arm or punching a wall till my hand is bloody and brusied just to get back into control of myself?

I think you are aware that it is a bad thing to ignore your anger. Self injury can be because of misdirected anger, and instead of hurting anybody else you hurt yourself, just to get rid of the anger. If your burning yourself like that, then it is time to seek out professional help. Your putting yourself at risk of infection and all kinds of problems. You could permanently hurt your hand too, and will have scars from all of those burns.
Most people do not understand self injury either, and you are going to have as hard time finding anyone who will. There are medications to help people control their anger hun, and it is far better then self injurious behavior.
please go see a doctor and I hope you stop hurting yourself out of anger.