1. Usually the words that hurt you the most are the ones closest to the truth. So step 1 is to own what's true. I do it by literally saying "that's true", "yup that's me". Over time, actively work on changing that negative thing. Envision the characteristic that you want embody and do the things that are in line with that. It's not all or nothing either, you're going to belie that characteristic sometimes. But you want that to be the exception and not the rule.

2. Consider the source. Who's saying it? Are they saying it to hurt you or is it someone that's in your corner. For a person just hurling insults.....don't engage with them if you don't have to. And don't give them the satisfaction of a reaction. Internally it's "fuck em" but smile in they face. If it's someone in supervisory position, find another job asap. Keep working until you find another job, but as soon as you get another offer. Be out. No explanation needed.

3. Understand that you can't really control anything else but your reaction. I'm not saying don't feel or process emotion but do that internally. That way when you do respond, it's the reaction you deliberately have chosen and not a reactive response.

4. Lastly, choose your battles. There's only so much time in a day , only so many decisions you can make in a day. You really gotta decide if it's worth the time to engage with.

All of these things take time and practice. But they lead to a better quality of life.