When people talk about you is because you’re doing something — whether good or bad, that’s up to you. If it’s the latter, why bother fighting back if you know you’ve done something bad or wrong? Lose no time arguing and use that time to fix it or improve so future times are better.
Similarly, when people talk shit about you or something you did. Why bother responding to these nonsense? All you can do is what’s in your control. Keep moving forward and doing you.
Haters gonna hate. (Cliché)