I get incredibly happy when I see anyone of the older generation dying
Don't you think being "extremely happy" is a little too much?
It's true but sometimes my heart feels like exploding when it's filled with a joy.
I don't know your reason why, but it is never a good idea to wish death on someone innocent, no matter their age. Everyone is human and deserve to live a long and healthy life, including you.
No one understands me. None of you have a brain. I'm at peace with my actions and I like that people die.
If you enjoy seeing people die you need some serious help. I suggest you to go see a therapist and talk to them about your feelings.