I think it might be over, I want to reach out to AP

My fiancé had an emotional affair with a coworker. She pursued, he reciprocated. I moved out when I found out, but we decided to try to reconcile. I remained moved out (we were living with his mum to save money and she has had an affair in the past so she sees absolutely nothing wrong with his behaviour and is painting me as unhinged) it’s been 3 months and he decided to “gently” cut contact, as in slowly stop engaging until she (the AP) called it all off on Wednesday night.

I’ve been really struggling with the fact he couldn’t just cut her off completely. And I think it might be over. I want to reach out to her. My entire life imploded. I’m the lowest and most hurt I’ve ever been. And absolutely nothing has impacted her.

I secretly got her phone number. This is what I am thinking of sending:

Hi AP, I am WS’s ex-fiancé and partner of 8 years. As you know, we were working through serious issues in our relationship, including his infidelity. I’m not reaching out to argue or trade insults. I’m reaching out because I think you deserve to understand the reality of what happens when you pursue an inappropriate connection with someone who is already committed. I’ve read the messages, listened to the voice memos, and seen the photos you shared. I know it never became sexual, but it did become emotional. Full of messages like “you’re just so great, I can’t imagine anything would go wrong for you” and “I’ve never met anyone like you, it’s so crazy I can’t stop thinking about you.” Those aren’t words shared between friends. They’re emotional commitments that belonged inside my relationship. What you chose to be part of wasn’t harmless. It was the dismantling of trust, the quiet rewriting of loyalty, and the erosion of something I built my life around. When you continued that connection knowing he was engaged, you became part of a lie that deeply hurt someone who believed she was safe. I’ve been left to pick up the pieces of a relationship I didn’t break. The impact doesn’t fade just because it wasn’t physical, it ripples through someone’s heart, their confidence, their sense of what’s real. I’m not asking for an apology. I just need you to understand that what happened wasn’t innocent. It was betrayal. And the pain it caused will take time to heal, even as I move forward with strength, clarity, and self-respect

Thoughts?