It would be easier for me to give advice if you gave me more concrete examples of the mistakes and the workplace or wherever you are being gossiped about.
Your mind now seems preoccupied about “my mistakes, my mistakes, my mistakes”. Can you see that you are making yourself more unhappy by replaying those past events and adding some of your own imagination?
People will talk and gossip about us whether we like it or not. My experience tells me that the more I worry that people gossip about me, the more likely it is to happen. Better to get something else to focus on now which brings you into the present moment.
Your self-talk sounds very negative. Can you notice that? The mind can be our enemy or friend? I know which one I prefer.