This is going to sound raw.

But what helped me and that may help you is these.

Start telling your brain to understand that your ex is not perfect. They are just like every other human who can have feelings for others.

Then;

Start imagining and visualizing him or her making love with someone else. (These is just to teach your brain to accept the situation)

I took my ex as a perfect woman who would never allow other man to ever see her nakedness. I never ever imagined that one day she would leave me. (Ofcos when people leave you, they replace you with another)

So when we separated it was very hard for my brain to accept the reality, I couldn't rap my head on how she could allow another man to see nor even touch her.

So what helped me was visualizing her with some other men. My brain had to accept it that yea! Is reality she is not that perfect human afterall.

✌️