Mellors this sounds like a good plan... at least you have something to pursue rather than feeling defeated in this, or having to make a decision that might be harmful to your son.

I also really like the idea of writing a letter but not sending it. Maybe sending it would have stirred up more problems, made her more determined in her lies, helped her justify her behaviour or something. I'm glad that writing it helped ease you.

This is a horrible situation and my heart goes out to you and mostly to your son, and hope this can come to a resolution whereby he can see you and spend time with you, get to know both parents, and he will be able to see things as they are. Good luck.