I can see that it is a truly heartfelt letter. Good for you in taking this first step.
For me, when working with DBers in drafting emails/letters, I believe strongly in letting you do the hard work on this yourself with several drafts and I offer it through guidance.
Before I post my feedback, input, and suggestions, I strongly recommend that you Google "making sincere amends" and look for some examples. Then come back with your second draft.
Generally speaking, I encourage DBers to whittle their letters down to 2 to 3 paragraphs at the most.
I do want to make a comment about letting go. You wrote:
So, that’s why finally, I want you to know that I completely and totally let you go. I let you go to find the life and love you want. I can think of no one more deserving of a healthy, nurturing family than you. I also let you go out of self-compassion. My holding on to hope has actually slowed down the pace of my growth and development as a man these last few months. And I know if there is ANY chance at friendship between us it will be after a long period of healing and growth.
What do you really want here? Let her go? Not want to reconcile with her? Yes? No?
My thoughts are the letter as it stands right now:
-Pleading and a bit too smothering -It has a smattering of superiority -There is no comment about healing -There is no comment on asking for amends
