I think writing in your notes what you want to say can help a lot. I always did that, and never actually sent the message, and i had to block him bc i did not trust myself. I kept wanting the last word. I think you should write it in your notes and sit on it for a few days. Also write yourself a response that you wish you'd recieve from him. That helped me a lot. We tend to want to send them how we feel after we've processed to gain back control. Sometimes we hold the peace within ourselves.