Many thanks to everyone who advised on whether or not to send a letter to my guy about his abuse. Before sending the letter, I had other (online) survivors and significant others of survivors read it and they really loved it and were quite moved.
I offered him all the support I could and said I was ready to listen if and when he ever needs it. I concluded by stating that I will stop contacting him if he continues to keep silence, as it is too painful for me, and also thanked him for the many ways he has helped me, without even realizing it.
It's been four days and he has not answered - Nevertheless, I'm glad that I've sent it. I said all that I wanted to say and more and no matter what happens, I know that someday, he won't hate me for writing it - It may give him the hope he needs, now or later.
Thanks again for your support.
"Become who you are." -Nietzsche