What is your take on good karma and bad karma? When you secretly wish ill on others, even if you don't act on it, does that make you bad?

There is this concept of revenge.

It isn't hard to understand or feel really.
But as a person raised on not throwing a rock back even if someone did throw a literal rock at me once, it kinda becomes hard to be nice the more years I spend on earth.

You know that idea that when you become a vampire, your feelings as a human are suddenly amplified? So when back as human you were able to keep things in and focus on the good, as a vampire it just stopped. So you kinda want to unleash pent up and well hidden emotions. So now you're easily frustrated and angered and somehow, there is this horrible sense of calm (like a horrifying hobby that oddly works) when you imagine bad things befalling on those who'd wronged you and those you love.

I am not saying it is right. But it just becomes tiring denying feelings, so you entertain them even if just on your head.

Being an adult is like that. It feels like it.

Is that just me? How do I become better as a person?

How do you burry that overwhelming desire for punishment to your enemies, for revenge (as what they call it)?

Sometimes, it makes me think. It is hard not to sin, admittedly, as a human.