^I agree with Mike.
I had a sponsor who with making amends, was really into trying and trying and trying..... To me I think that causes the other person harm and misses the whole purpose of amends.
You could maybe write him a brief letter if he won't see you, but honestly ask yourself if receiving a letter from you would cause him more harm since it sounds like he wants to be left alone.
It was suggested to me by my other sponsor to write a certain amends that couldn't be made in a letter, tie it to a balloon, and put it out in the universe to be free of it.