I want to cut up this girls stuff
You mean you want to ruin her possessions?
My friend told me to do it because he was so pissed off
Destroying someone's property could get you in a heap of trouble. You could be sued or even arrested and made to to pay for the things you destroyed.
That just makes me want to do it more. I feel good about it.
You sound seriously self-destructive. You should seek out counseling before your inclinations and actions ruin your life.