How to stop obsessing about what people say

I had emailed my exnarc exwife warning her about what his plans were because of modification of child support and moving out of state. She fwd to her dad. He replied to me saying she didn't want to respond but he thought he would. He thanked me for my concern. He said he didn't want to sound judgmental but someone who messes with a married person has the same thing happen to them. That ex probably has a new love in the new state. Saying good luck getting support from him.

At first it didn't bother me. I had to respond telling my side. It's as if he was insinuated I was a husband stealer. I am not. My exnarc said he was unhappy, marriage long over, she's not nice...etc. he was in process of moving out and starting a divorce. I told him I think he's a narcissist and doesn't love or care about anybody and did tell him he has a new victim .

I can't get this out of my head. I think he's pulled this shit with ex wife many times before. Ex told me once he would do everything to make her break up with him and shed always forgive and take him back. I'm overthinking what he said, like I deserved this or something.

NC from all of from now on. The kids are half brothers and I was hoping they could be a part of eachothers lives. I need to forget about it. How to get these pcs thoughts away? His lies are mountains tall and unreal.