how to be a bad person?

回答的话很简单,
If you're sick of being a good person,then by all means do become a 'bad' person.
But,how do you define a "good person" and a "bad person" anyway?Being "kind" to others doesn't mean you're a "good" person.For god knows what you can be a murderer or a thief (of course this,I don't mean you).
Similarly,standing up for your own believes and fighting back,shows one's strength,and would you not say that's a "good" thing?
My 2 cents of advice,is that you give a break on trying so hard to be a "bad" person,but rather focus on why they've cheated you.Was it because you were too easy of a target?If so,gear yourself up and defend yourself from these people.
Wishing you the best of luck.
P.S.This world is never fair.Remember that.