I'm glad a guy who bullied me in school is now dead
How could you say such a thing? What did it make you feel that he died?
I feel happy when someone who made my life miserable is dead.
It is hard to feel bad when something happens to the person who made your life miserable but it is not good to be happy that somebody is dead. They had people who loved them and cared for them and it is not good to be happy about their sadness.
Fuck that guy. He was the one who said mean things to me. I always hated him.
Even though your schoolmate wasn't nice to you, being glad about his death is morbid and cruel. Have some compassion for those who hurt you so that you don't inflict yourself with your own inner anger and rage.