I just re-read your thread (sorry I can't keep everyone’s story’s straight).
So you have had time to read the boundary thread and have several examples.
The best thing you can do is draft up what you want to say, post it here for review. We can help tweak it. Then you can practice it alone. Then say it when ready.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712