Honestly consider which kind of antidote would work best, for that specific kind of poisonous-meaning.
Just a couple of examples, to "prime the pump", as it were..
IF the poison were white-supremacist evil, THEN the antidote might be that guy .. Daryl is his name, perhaps, who deliberately makes friends with KKK people, & gets them to honestly change.
( if there ever was an example of what the ultra-woke socialist felon Yehoshua "Jesus" benJoseph meant, in his relationships with people, this guy is demonstrating it. : )
IF the poison is the psychopathic machiavellianism of for-profit-corporations, THEN the antidote might be that investigative journalism exists, & deliberately reading "The Elements of Journalism" ( 4th edition, now, I think ), & helping to get other citizens-of-our-world competent in understanding journalism, & how it is the immune-system our world needs, right now.
IF the poison is child-abuse .. THEN .. this one's difficult: it hurts too deep, doesn't it? .. then .. simultaneously protection for children ( like that operation which liberated a whole bunch of girls from a trafficking-ring, the other year, or like help-lines for children, so they've got a lifeline to call, or like organizations/people who systematically make-accountable the perpetrators, reducing the number of them who are out ), those ( individual & institutional ) who force-the-perpetrators into visibility, thus "removing their accommodation", to be .. diplomatic .. about it, or lobbying for better legislation, or making-certain that therapy is both available and successful for survivors of abuse ( some "charities" just purport to do good, & obliterate opportunity while consuming resources padding their administration's ass by design, & torpedoing those scum would improve our world, markedly )
Anyways, you need to discern which antidote you need to be applying, & you need to understand that some lives get caught in stuff sooo horrific that even witnessing it can mangle a life..
That is the actual current condition of our world, our ocean-of-lives.
To alter our world, our world's ocean-of-lives, we need to deliberately turn the tide, and that means forcing the tide to go against the way that DarkHexad, the 6 dimensions of human evil that I've found so-far, wants:
Countering ANY of these dimensions from remaining in authority on our world is good, countering the entanglement network of multiple-dimensions, together, is better, but!..
Remember Stephen R. Covey's principle!
IF your Circle of Concern is too big, THEN it is draining you, making you helpless!
IF you deliberately & strategically reduce your Circle of Concern, .. THEN .. your Circle of Influence will, as you recover, grow!
And you have your balance to earn: my balance isn't relevant to your condition, neither is your balance relevant to how I'm managing, etc.
Each is independent of others, & the whole "I'm this-way therefore you ought be, too" herd-bullying has no actual validity.
I hope that you find stable balance, & I hope that someday you become able to directly & significantly counter whatever harm/evil it is you witnessed.