Most of us handle an unwanted thought the same way: we try to shove it out. Stop worrying about the meeting. Stop replaying what they said. A minute later it's back.
There's an old image for this. A restless mind is like a wild horse. Put a fence in front of it and it simply jumps. Force doesn't tame it. What works is quieter: a light hand on the reins, a kind word, and somewhere better to go. You can't delete a thought. You can choose the next one.
It helps to break it into three small moves. Stop, as if standing on a platform watching your train of thought go past. Observe whether it's a thought you'd actually choose. Then steer, gently, by putting a different, more useful thought in its place. It won't take the first time. These grooves were worn over years, and the part of you that chooses only gets steadier with use.