I'm of the opinion of not leaving things unsaid. I've left things unsaid and not had the opportunity to rectify it. Regret is a bitter pill to swallow.
The way I see it (and this may sound harsh, it's not intended, i'm running on about three hours of sleep) you have three choices:
1. You can write the letter to him and send it. What happens will happen. 2. You can write the letter and not send it as a way of forgiving yourself and getting it off your chest. 3. You can not write the letter and wonder what if.
I mean, imo, the worst thing he can do is continue to do what he's doing, which is receive the letter and not talk to you.
Is there any harm in doing it?
M:32,H 32 T:10, M5 BD/H Move Out: 9/2014 - extreme anger H Mental Illness Diagnosis: 4/15 Served D Papers: 10/15 Divorced: 11/15